To be effective, an exercise program must be
a. uniquely tailored to every person
b. maintained at a constant level of difficulty
c. applied generally to whole-body fitness
d. constantly increasing in difficulty

To be effective, an exercise program must be (a) uniquely tailored to every person. This is due to the fact that each person has a unique body as well, what could be an effective regimen to one person may not be as effective as another. Each person's health has to be taken into consideration as well since some health issues may need special attention.

Her parents start noticing changes about her. she's probably just competive though not on drugs

The answer i think would be diet coke