Answer:
(A). Nucleotides
Explanation:
The nucleotides are the basic unit in formation of DNA and RNA. The both nucleic acids contain nucleotides with different nitrogenous bases. The nucleotide consist of ribose sugar, phosphate and a nitrogenous base.
The ribose sugar is present in the RNA and deoxyribose in the DNA. In the absence of phosphate group, the ribose sugar and nitrogenous base forms a nucleoside.
