Question

all living things use nitrogen to
a reproduce.
b make sugar.
c make proteins.
d transport water.

Explanation:

Nitrogen is a key component of amino - acids, which are the building blocks of proteins. All living things use nitrogen to make proteins. Reproduction involves genetic material and cell - division processes not directly related to nitrogen in this way. Sugar is made mainly from carbon, hydrogen, and oxygen. Water transport is related to structures like xylem in plants and not directly to nitrogen.

Answer:

C. make proteins