Which Is a Difference Between Fast-Twitch Fibers and Slow-Twitch Fibers

Multiple Choice

Which is a difference between fast-twitch fibers and slow-twitch fibers?

A) Fast-twitch fibers are more common in the leg muscles of champion sprinters than of marathon runners,and the reverse is true for slow-twitch fibers.
B) Fast-twitch fibers have more mitochondria.
C) Fast-twitch fibers fatigue less rapidly.
D) The abundance of fast-twitch fibers is more a product of training than of genetics,and the reverse is true for slow-twitch fibers.
E) Fast-twitch fibers are more common in postural muscles than in finger muscles,and the reverse is true for slow-twitch fibers.