By the age of 18, the typical american has seen or heard more than alcohol advertisements on television, in print, and on the radio 250,000 200,000 300,000 100,000

I think the answer is 250,00

Answer key says 100,000, but really it can be either one of these if you really think about it.

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)

A. vitamin c is your answer