Meaning: 'Aesthetic' relates to the appreciation of beauty or good taste, particularly in design.

Wrong options:

• settled: 'Settled' is an adjective that means established or resolved, which does not relate to the visual appeal of features.
• credentials: 'Credentials' refers to qualifications or achievements, which does not fit the context of features in architecture.
• incorporate: 'Incorporate' is a verb meaning to include or integrate, which does not describe a type of feature.
• complicated: 'Complicated' is an adjective that means difficult to understand or deal with, which does not describe features in a positive light.
• baulk: 'Baulk' is a verb meaning to hesitate or refuse to proceed, which does not fit as a descriptor for features.
• ethos: 'Ethos' refers to the characteristic spirit of a culture or community, which does not apply to physical features.
• practical: 'Practical' is an adjective that refers to being useful or sensible, which does not capture the essence of beauty or aesthetics.

Correct answer: complicated

Explanation: The term 'complicated' is used as an adjective to describe how eco-friendly building design has made matters more difficult. It fits grammatically and contextually, as it indicates an increase in complexity in the architectural process.

Meaning: 'Complicated' means something that is difficult to understand or deal with due to its complexity.

Wrong options:

• settled: 'Settled' does not convey an increase in complexity; it suggests something that has been resolved or established.
• credentials: 'Credentials' does not relate to the complexity of matters; it refers to qualifications or achievements.
• incorporate: 'Incorporate' is a verb that means to include, which does not describe the state of matters.
• aesthetic: 'Aesthetic' refers to beauty, which does not fit the context of increasing complexity.
• baulk: 'Baulk' is a verb meaning to hesitate, which does not describe the state of matters.
• ethos: 'Ethos' refers to the spirit of a culture, which does not relate to complexity in design.
• practical: 'Practical' means useful or sensible, which does not convey the idea of increased complexity.

Correct answer: incorporate

Explanation: The verb 'incorporate' means to include or integrate elements into a design. It fits grammatically as it follows the structure of the sentence, indicating what architects are expected to do regarding ecological elements.

Meaning: 'Incorporate' means to include something as part of a whole.

Wrong options:

• settled: 'Settled' does not fit as it is not a verb that describes an action architects would take.
• credentials: 'Credentials' is a noun and does not fit grammatically in this context as an action.
• complicated: 'Complicated' is an adjective and does not describe an action that architects can perform.
• aesthetic: 'Aesthetic' is an adjective that does not convey an action related to design.
• baulk: 'Baulk' is a verb meaning to hesitate, which does not fit the context of actively including elements.
• ethos: 'Ethos' is a noun that does not describe an action architects would take.
• practical: 'Practical' is an adjective and does not convey an action related to design.

Correct answer: credentials

Explanation: The word 'credentials' refers to the qualifications or achievements that enhance the reputation of a building. It fits grammatically as a noun that complements the context of ecological aspects in architecture.

Meaning: 'Credentials' refers to the qualifications or achievements that validate or enhance something's reputation.

Wrong options:

• settled: 'Settled' does not fit as it refers to something established, not a measure of ecological value.
• incorporate: 'Incorporate' is a verb and does not fit as a noun in this context.
• complicated: 'Complicated' is an adjective that does not describe a measure of ecological value.
• aesthetic: 'Aesthetic' refers to beauty, which does not relate to the qualifications of a building.
• baulk: 'Baulk' is a verb meaning to hesitate, which does not fit as a noun in this context.
• ethos: 'Ethos' refers to the characteristic spirit of a culture, which does not fit as a measure of ecological value.
• practical: 'Practical' is an adjective that does not describe qualifications or achievements.

Correct answer: baulk

Explanation: The verb 'baulk' means to hesitate or refuse to proceed with something. It fits grammatically as it describes the action of architects in relation to requirements they may face.

Meaning: 'Baulk' means to hesitate or refuse to proceed with something, especially due to reluctance.

Wrong options:

• settled: 'Settled' does not fit as it refers to something established, not an action of hesitation.
• credentials: 'Credentials' is a noun and does not describe an action architects would take.
• incorporate: 'Incorporate' is a verb meaning to include, which does not convey hesitation or refusal.
• complicated: 'Complicated' is an adjective that does not describe an action related to hesitation.
• aesthetic: 'Aesthetic' is an adjective that does not convey an action of hesitation.
• ethos: 'Ethos' is a noun that does not describe an action architects would take.
• practical: 'Practical' is an adjective that does not describe an action related to hesitation.