Which of the following drug is commonly used in narcoanalysis ?: (A) Atropine sulfate, (B) Scopolamine hydrochloride, (C) Phenobarbitone, (D) Morphine
Answer is B. Controlled administration of intravenous hypnotics to obtain information from subjects who are unable or unwilling to provide it otherwise, is known as Narcoanalysis or Narcosynthesis.
Drugs used for narcoanalysis are:

Ethanol
Scopolamine
Temazepam
Barbiturates like Thiopentone and Amobarbital

These drugs are also known as truth drug or truth serum.

Phenobarbitone is not used, rather amobarbital is used for narcoanalysis.