Kavar Recently Participated in a Marketing Study, but Was Unaware

Multiple Choice

Kavar recently participated in a marketing study, but was unaware of what group he was in. Later, he was informed that even the marketing administrators running the study were unaware of what group Kavar was in at the time of the study. This is an example of:

A) a single-blind procedure.
B) a double-blind procedure.
C) a repeated measures design.
D) a planned contrast.