In DNA, the designations 3' and refer to the
A)carbon or nitrogen atoms on the rings of purine or pyrimidine bases.
B)bonding between purines and deoxyribose and between pyrimidines and deoxyribose.
C)cross-linking of the third and fifth carbon atoms of deoxyribose.
D)carbon atoms of deoxyribose to which phosphate groups may bond.
E)bonds that form between adenine and thymine and between guanine and cytosine.