Metabolic waste is....?

Question

[a] the by-product of chemical reactions in the organism

[b] useful to the body

[c] part of metabolism that is used by the organism

[d] important for building proteins

[e] removed by secretion

Answer 1

a..

Answer 2

[a] the by-product of chemical reactions in the organism.

Answer 3

My mom said it was A.

Answer 4

Actually, [a] AND [e] are both pretty much equally correct, except that not ALL waste is removed by secretion.