Meaning: 'Establish' means to set up or create something on a firm or permanent basis, in this case, environmental policies.

Wrong options:

• cater: Cater means to provide or supply something, usually in the context of food or services, which does not fit the context of implementing policies.
• enlist: Enlist means to enroll or recruit, typically for military service or participation, which does not convey the action of creating or implementing policies.
• enrol: Enrol means to register or sign up, which is not appropriate in the context of actively setting up environmental policies.

Correct answer: practice

Explanation: The term 'practice' is appropriate here as it refers to established methods or procedures, particularly in a professional context. It fits grammatically as a noun that complements 'best' to form the phrase 'best practice,' which is commonly used in discussions about standards and procedures.

Meaning: 'Practice' in this context refers to a method or way of doing something that is accepted as correct or effective, especially in a professional setting.

Wrong options:

• vocation: Vocation refers to a person's occupation or profession, which does not fit the context of environmental policies and practices.
• code: Code typically refers to a system of rules or principles, which does not align with the idea of established methods or practices in this context.
• revision: Revision means the act of reviewing or altering something, which does not convey the idea of established methods or practices.

Correct answer: concern

Explanation: The word 'concern' fits grammatically as a noun that indicates a matter of interest or importance, which aligns with the context of companies being able to prioritize environmental issues. It logically follows the structure of the sentence, indicating what profitable companies can afford to focus on.

Meaning: 'Concern' refers to a matter that is important or requires attention, in this case, the environment.

Wrong options:

• level: Level refers to a position or rank, which does not convey the idea of prioritizing or focusing on environmental issues.
• effect: Effect refers to a change that is a result of an action, which does not fit the context of actively caring for the environment.
• bother: Bother means to take the trouble to do something, which does not appropriately convey the seriousness of prioritizing environmental issues.