If someone is predisposed to a disease, they are more likely to contract the disease due to
a. lifestyle choices
b. heredity
c. random chance
d. factors other than heredity or lifestyle

The best answer is B.

If a person is predisposed to a particular disease, they are most likely to catch that disease due to heredity. This is called genetic predisposition.

Genetic predisposition sometimes also called genetic susceptibility, is an increased likelihood of developing a particular disease based on  person's genetic makeup.

Genetic predisposition results from some specific genetic variations that are often inherited from parents. These genetic changes contribute to the development of a disease but do not cause it.  Some predisposed  people will never get the disease while others with same predisposition will get it, even within the same family.

the answer is b.) hydrogen bonds between bases.

the answer is d. none of the above