The area of the city where retail and office activities historically were clustered was the

Central buisness district

Explanation:

d is the correct answer.

b is incorrect because it makes food by itself

c is incorrect because us humans don't know how to produce their own food using the sun like plants.

a is incorrect because consumers can depend on carnivores for eating food for consumers to eat the dead organism. same thing with omnivores.

well this isn't a question but if you are asking if it is true or false it is, true.