Heredity is best described as a. the single-most important influence on skill-related fitness b. natural ablities that cannot be changed c. highly mutable personal characteristics d. none of the above

Basically, heredity refers to the biological traits that we get from our parents in the process of reproduction. Therefore, these traits are not learned nor related to skills, but are innate abilities that we cannot change. These are the traits that we get through our parents' genetic information. For example, the color of our eyes or the shape of our nose depends on physical traits of our parents too. Answer for this would be B.