The correct option is
A Smack
"Hard drug" has been used to categorize drugs that are addictive and injectable, notably, heroin, cocaine, and crystal methamphetamine. These impurities make brown sugar much cheaper than the typical, more purified, the form of heroin; they create a substance more dangerous than heroin, as the user is unsure exactly how much heroin he is consuming.
So the correct answer is 'Smack'.