Why is the use of the club drug rohypnol considered an example of drug synergy?

(1 point)
Responses

a. Using alcohol cancels the effects of rohypnol.

b. Rohypnol is often mixed with alcohol.

c. One club drug taken with another reduces their effects.

d. Loud music in clubs enhances the effects of rohypnol.

b. Rohypnol is often mixed with alcohol.