Answer:
The correct answer is B) A and T pair together because their ratio is close to 1.0 in almost all organism.
Step-by-step explanation:
There are 4 principle nitrogen bases present within a DNA molecule.Among them 2 are termed as purine bases such as adenine and guanine and rest of the two are called pyrimidine bases such as thymine and cytosine.
Adenine pairs with thymine by 2 hydrogen bonds whereas guanine pairs with cytosine with 3 hydrogen bonds.
According to the given question the ratio of adenine to thymine is close to 1 in almost all the organism.As a result Adenine and Thymine will pair together.Because in a DNA molecule the more efficient base pairing occur between two complementary bases whose ratio is 1 or very close to 1.