DrSchultze Conducts Research on the Effects of a New Drug

Multiple Choice

Dr.Schultze conducts research on the effects of a new drug on obsessive-compulsive disorder.In his study,neither Schultze nor the participants knows who is receiving the active drug and who is receiving the placebo.This example describes

A) random sampling.
B) a double-blind study.
C) a single-blind study.
D) control factor.
E) social desirability bias.