Mary is an undergraduate student who has volunteered for a study her professor is running. During the study,Mary picks up on cues from her professor about the expectations he has regarding the outcome of the study. The professor does not realize that she is picking up on them, yet she behaves as he expects. Which of the following phenomena has occurred?

a. Mary’s professor had experienced sampling bias.
b. Mary’s professor is demonstrating confirmation bias.
c. Mary has participated in a double-blind study.This answer is incorrect.
d. Mary’s professor has experienced hindsight bias.
e. Mary has displayed demand characteristics.