The answer is C. 19 to 26 the actual age people reach their physical peak is 26 which therefore is C as your answer.
I think that the answer is D. Dieting because dieting helps your body eat more things that are good for it and, less things that are bad for it. It can make your skin clearer, and help you feel good overall which is a physical health help trait.
C. Sensitivity
because this isn't a constant thing, so it isn't a. it isn't b. and it isn't d.