Final answer:
option d,Cytosine and guanine (C and G) represents an actual base pair with the largest number of hydrogen bonds in DNA.
Step-by-step explanation:
The base pair with the largest number of hydrogen bonds is cytosine and guanine (C and G).
In DNA, hydrogen bonds are formed between complementary base pairs. Adenine (A) always pairs with thymine (T), forming two hydrogen bonds, while cytosine (C) always pairs with guanine (G), forming three hydrogen bonds. These hydrogen bonds help stabilize the DNA double helix structure.
In this case, option D, cytosine and guanine, represents the actual base pair with the largest number of hydrogen bonds.
The base pair that represents an actual base pair with the largest number of hydrogen bonds is Cytosine and Guanine (C-G). In the structure of DNA, complementary bases form hydrogen bonds with one another, which contribute to the stability of the DNA's double helix structure. According to the information provided, adenine (A) and thymine (T) form two hydrogen bonds, while Cytosine (C) and Guanine (G) form three hydrogen bonds. Therefore, the correct answer is Cytosine and Guanine, which is choice D.