François was dismayed to discover that some of his football teammates were using drugs to enhance their footwork and endurance on the playing field.Which of the following drugs were the players most likely using?

A) morphine derivatives
B) marijuana
C) amphetamines
D) barbiturates

Amphetamines are stimulant drugs that can improve physical performance, including endurance and reaction time. Morphine derivatives and barbiturates are depressant drugs that would likely impair performance, and marijuana can have unpredictable effects on physical and cognitive abilities.