Respuesta :

Answer:

A. Hydrogen Bond

B. Adenine

C. Guanine

D. Thymine

E. Cytosine

Explanation:

The double helix is held together in the middle by hydrogen bonds that connect the different bases together. There are 4 bases that make up a DNA, guanine, cytosine, thymine and adenine. Each base pairs up with a specific base because each of them have a distinct shape. Adenine matches up with Thymine, while Guanine matches up woth Cytosine.