Nucleic acids and proteins both contain which element as one of
their main elements?
А
Nitrogen
B
Iron

A. Nitrogen

Explanation: Nucleic acids contain the same elements as proteins: carbon, hydrogen, oxygen, nitrogen; plus phosphorous (C, H, O, N, and P). Nucleic acids are very large macromolecules composed of repetitive units of the same building blocks, nucleotides, similar to a pearl necklace made of many pearls.

yes the words are placed in front