Double-Blinding in Experiments Is Important So That

Multiple Choice

Double-blinding in experiments is important so that
I. The evaluators do not know which treatment group the participants are in.
II. The participants do not know which treatment group they are in.
III. No one knows which treatment any of the participants is getting.

A) I only
B) III only
C) II only
D) I, II, and III
E) I and II