Question

what are the components of dna?
(a) phosphate group, sugar, and nitrogen base
(b) carbon, oxygen, and hydrogen
(c) sulfur, iron oxide, and acid
(d) carboxyl group, amino group, and r group

Explanation:

DNA is a nucleic acid. Nucleic acids are made up of nucleotides. Each nucleotide consists of a phosphate group, a sugar (deoxyribose in DNA), and a nitrogen - containing base.
Carbon, oxygen, and hydrogen are elements that make up many organic compounds but are too general to specifically describe DNA's components. Sulfur, iron oxide, and acid are not components of DNA. Carboxyl group, amino group, and R group are components of amino acids (the building blocks of proteins), not DNA.

Answer:

A. Phosphate group, sugar, and nitrogen base