Bob Has Been Sedentary for Several Years

Bob has been sedentary for several years. As a New Year's resolution, he starts an intense exercise program, but after three months he stops exercising completely. What was the likely effect of the program on his heart mass while he was exercising, and what is the most likely outcome a year later?

A) His heart mass most likely increased during the exercise program and has remained at the same larger size.
B) His heart mass most likely increased during the exercise program and then decreased to its previous size.
C) His heart mass most likely decreased during the exercise program and has remained at the same smaller size.
D) His heart mass most likely decreased during the exercise program and has increased to its previous size.