Which term best describes the systems in an animal's body?

A. extraneous

B. interchangeable

C. interconnected

D. segregated

B. interconnected

Explanation:

All the systems in our bodies (humans are indeed animals) are connected with each other to create a functional being. The blood flows throughout the body, providing nutrients; the bones support the structure and protect the heart and lungs. They work together.

Why not A: The systems are all completely necessary. There's nothing extraneous in our bodies, because extraneous stuff takes up energy, and our biology is incredibly economical.

Why not B: They're not interchangeable. How would you like your bones to turn to blood? Uh-huh.

Why not D: They interact with each other consistently, so they're not separate or segregated.