Fast-twitch, fatigable motor units (FTF) ______?
1) a have large cell bodies and innervate a large number of slow-twitch fibers
2) b have large cell bodies and innervate a small number of slow-twitch fibers
3) c have small cell bodies and innervate a small number of type II muscle fibers
4) d have small cell bodies and innervate a small number of SFR muscle fibers
5) e have large cell bodies and innervate a large number of type IIB muscle fibers