Answer:
B. narcotics
Step-by-step explanation:
Narcotics are a class of drugs which induce sleep, relieve pain etc. without leading to comatose. The patient also perceives actual surrounding.
Option A is incorrect because hallucinogens give out of this world feeling and person does not perceive the actual surrounding when he uptakes hallucinogens. Stimulants rather than causing sleep lead to more neurological activities so option C is also incorrect. Barbiturates lead to similar kind of impact as of narcotics but they may lead to comatose so option D is also incorrect.