This is the only stimulant listed that is also a hallucinogen. It less directly impacts dopamine like the other stimulants, and largely affects serotonin release in the brain. a. Methamphetamine

b. Crack

c. Caffeine

d. MDMA (ecstasy)

If you were running a marathon, which type of muscle fibers would be most useful to you? a. slow-twitch b. fast-twitch, type i a c. intermediate-twitch, type ii b d. slow-intermediate twitch, type i b select the best answer from the choices provided. a b c d