The correct option is
D a-t; b-r; c-p; d-q
(a) Opiates are derived from opium, the dried latex of poppy plant. Heroin is a semisynthetic opiate obtained from acetylation of a natural opiate morphine.
(b) Benzedrine and Methedrine are synthetic stimulants which stimulate nervous system and increase alertness and excitement.
(c) Ganja and Charas are hallucinogens obtained from Cannabis sativa (Hemp).
(d) Nembutal A and seconal are barbiturates, a type of sedative drugs that induce sleep. These are depressants of central nervous system and lower the activity of brain leading to sleep.
So, the correct answer is 'a-t; b-r; c-p; d-q'.