Smack is chemically:

The correct answer is Option (1) → Diacetyl morphine

Smack is another name for heroin. Heroin belongs to the opioids, the drugs that bind to opioid receptors in the central nervous system and the gut. It is made by acetylation of morphine, which is taken from the latex of the poppy plant Papaver somniferum. It is a depressant and slows down body functions.

Option (1) Diacetyl morphine — Correct. Heroin, commonly called smack, is chemically diacetylmorphine, a white, odourless, bitter crystalline compound. It is obtained by acetylation of morphine, extracted from the latex of the poppy plant.

Option (2) Cocaine — Incorrect. Cocaine is an alkaloid from the coca plant Erythroxylum coca of South America. It interferes with the transport of the neurotransmitter dopamine and stimulates the central nervous system. It is a stimulant, not heroin.

Option (3) Benzodiazepine — Incorrect. Benzodiazepines are medicines used to help patients cope with mental illnesses such as depression and insomnia (sleeplessness). They are often misused, but they are not heroin.

Option (4) Amphetamine — Incorrect. Amphetamines are stimulant drugs, also used as medicines for conditions such as depression. They are not heroin.

Note: A similar question was also asked in CUET (UG) 2026 on 26-05-2026 (Slot 1).

NCERT Extract:
Drugs and Alcohol Abuse – “Opioids are the drugs, which bind to specific opioid receptors present in our central nervous system and gastrointestinal tract. Heroin (Figure 7.7), commonly called smack is chemically diacetylmorphine which is a white, odourless, bitter crystalline compound. This is obtained by acetylation of morphine (Figure 7.7), which is extracted from the latex of poppy plant Papaver somniferum (Figure 7.8).”