This describes something that is complicated, difficult, or consists of interrelated parts. example: linda needed the teacher to explain the relationship between the plot and the subplots.

Complex

Explanation:

When we describe something as "complex," we mean one of two things. On the one hand, it is possible that we mean that something is very difficult to do or to solve. However, we can also mean that something consists of various interrelated parts, such as a "complex" machine. Therefore, this is the word that would best fit in the example given.

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.