The best way to protect yourself from date-rape drugs is to
a. leave your drink unattended.
b. take open drinks from strangers.
c. drink a beverage that is foaming and odd-colored.
d. leave the drink given to you by a stranger in the garbage.

D.

Explanation:

Leaving your drink unattended would provide the opportunity for someone to slip a pill in it, taking drinks from strangers is dangerous because you did not see them pour it and it could already be drugged, and drinking a foaming and odd colored drink is dangerous because it is showing signs of being tampered with.

D. is the only safe answer in this scenario; throw away any drinks given to you by a stranger.

I hope that this helps you in the future, and that this can become common sense that will keep you safe.