B. Protein
Amino acids are organic compounds that combine to form proteins. Amino acids and proteins are the building blocks of life. When proteins are digested or broken down, amino acids are left. The human body uses amino acids to make proteins to help the body: Break down food.
C.The unique role the species plays in an ecosystem .
The best answer to go with is b
They are heterotrophic- not photosynthetic because they cannot perform photosynthesis