Answer : 3. "Phoebus Levene"
Explanation :

Answer: C) Phoebus Levene Explanation: Deoxyribonucleic acid (DNA) is a nucleic acid polymer composed of monomers called nucleotides. Nucleotides are composed of three components: (1) a pentose sugar; (2) a nitrogenous base; and (3) one to three phosphate groups. Phoebus Levene, a Russian biochemist was the first to discover the nucleotide and the first to correctly identify the way nucleic acid molecules, DNA.