Regular exercise often leads to an improved body image.

That's true!

Regardless of your fitness level, it can improve your body image so much!

Isn't it cool, the fact that only working out and exercises can change your body? Surely you've seen commercials on TV where these people say "Use this treadmill like the way I did to lose weight" or "I've lost x amount of pounds using this work-out machine"

It works! :D

↑   ↑   ↑ Hope this helps!

b) the heart is a pump made of muscle and that is difficult to grow in the lab.

the right answer is: time