Answer:
The correct answer is age.
Step-by-step explanation:
A risk factor is everything that makes a person more susceptible to having a health problem or disease.
For example, a person who consumes a lot of fat may be more prone to heart problems.
Sometimes these risk factors can be controlled or avoided, as we saw in the example, that person could stop eating fats.
But there are things that cannot be controlled, in this case: age.
Nothing can prevent a person from aging and that with age brings susceptibility to certain types of diseases.
Given this information the correct option is Age.