Choose the correct statement about licensed veterinarians in the united states.

a. they must choose a specialty.
b. they must be certified by the avma.
c. they can treat all nonhuman animals.
d. they can treat only animals specified on the license.

b is wrong i took the test

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)