How do these two events relate to each other?

I need two events relate to each other

Explanation:

so I can answer the question

buying socks and buying shoes are independent events.

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.