Answer:
A. Hydrogen Bond
B. Adenine
C. Guanine
D. Thymine
E. Cytosine
Step-by-step 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.