Meaning: Decline means a gradual decrease or reduction in something, in this case, marriage rates.

Wrong options:

• calculation: 'Calculation' refers to the process of determining something mathematically, which does not relate to the context of marriage rates.
• significance: 'Significance' refers to the importance of something, which does not fit the context of a numerical change in rates.
• decrease: 'Decrease' is a noun that could fit, but 'decline' is more commonly used in this context to describe a reduction in rates.

Correct answer: decrease

Explanation: The word 'decrease' is appropriate here as it directly refers to a reduction in the proportion of the population that is married, fitting both grammatically and contextually with the preceding sentence.

Meaning: Decrease means a reduction in size, amount, or number, which accurately describes the change in the proportion of married individuals.

Wrong options:

• view: 'View' refers to an opinion or perspective, which does not relate to the statistical change in marriage rates.
• change: 'Change' is too vague and does not specifically indicate a reduction, making it less precise than 'decrease.'
• multiplication: 'Multiplication' refers to an increase through a mathematical operation, which contradicts the context of a reduction in marriage rates.

Correct answer: increased

Explanation: The word 'increased' fits grammatically and contextually as it indicates a rise in the proportion of the population who were never married, aligning with the overall trend discussed in the passage.

Meaning: Increased means to become greater in size, amount, or number, which accurately describes the rise in the percentage of never-married individuals.

Wrong options:

• doubled: 'Doubled' implies a specific increase by a factor of two, which is not supported by the data provided in the text.
• rounded: 'Rounded' refers to adjusting a number to the nearest whole number, which does not apply to the context of population statistics.
• divided: 'Divided' suggests a separation into parts, which does not fit the context of an increase in population proportions.

Correct answer: who

Explanation: The word 'who' is the correct relative pronoun to refer to people, fitting grammatically and contextually as it introduces the clause about the population that was widowed.

Meaning: 'Who' is used to refer to people, making it appropriate for discussing the population in question.

Wrong options:

• where: 'Where' refers to a place, which does not fit as it does not relate to the subject of people being widowed.
• when: 'When' refers to time, which is not relevant in this context as it does not pertain to the population being discussed.
• which: 'Which' is used for things or animals, making it less appropriate than 'who' when referring to people.