Why do you think carbon has an entire branch of chemistry devoted
to its study?

the three components of a nucleotide are the nitrogenous base, the phosphate group and the five-carbon sugar.

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds

i believe your answer would be c.. : )