Nucleic acid can be synthesized only in the direction of
3-3
3-5
5-3
5-5
Explanation for correct option
(C) 5-3
Explanation for incorrect options
(A) 3-3
(B) 3-5
(D) 5-5
Hence, the correct option is (C) .Nucleic acid can be synthesized only in the direction of 5-3.