Question

which nitrogen base binds with cytosine? a guanine b adenine c uracil d thymine

Explanation:

In DNA, nitrogen bases pair specifically. Cytosine (C) pairs with guanine (G) through three hydrogen bonds. Adenine (A) pairs with thymine (T) in DNA and with uracil (U) in RNA. Thymine is specific to DNA and pairs with adenine. Uracil is in RNA and pairs with adenine.

Answer:

A. guanine