2
3
4
1
Answer is Wrong!
Answer is Right!
The correct answer is A. 2.
Guanine and cytosine are complementary bases in DNA. They form hydrogen bonds with each other, which help to hold the DNA double helix together. Each guanine base forms three hydrogen bonds with a cytosine base.
The other options are incorrect. Option B is incorrect because guanine and cytosine form two hydrogen bonds, not three. Option C is incorrect because guanine and cytosine do not form four hydrogen bonds. Option D is incorrect because guanine and cytosine do form hydrogen bonds with each other.