Answer:
A
Step-by-step explanation:
The DNA is made 4 nitrogenous bases. A (adenine) pairs with T (thymine) and are held by two hydrogen bonds. C (cytosine) pairs with G (guanine) and are held by three hydrogen bonds.
You might wanna remember this by the preposition 'at', which ultimately makes C and G together. Or you might wanna remember it by something like G- CAT.