Question

which element is found in both dna and protein?
sulfur
sodium
nitrogen
chlorine

Explanation:

DNA is composed of nucleotides which contain nitrogen - containing bases. Proteins are made of amino acids, and amino acids have nitrogen in their amino group. Sulfur is sometimes in proteins (in cysteine and methionine) but not in DNA. Sodium and chlorine are not major elements in either DNA or proteins.

Answer:

C. nitrogen