Fact 1: Caffeine is a central nervous system stimulant.

Fact 2: Likewise, the caffeine and saccharose stimulate the body's stimulation of serotonin.

Given the two facts above, answer the question "What is a central nervous system stimulant?" with the following options: 
- saccharose
 - barbiturates
 - cigarettes
 - sweating
 - muscle relaxants
 - A Greek letter
 - Decibels
 - valium


 

 saccharose        