Lin Is Taking a Course Where Everyone Who Participates in Class

Lin is taking a course where everyone who participates in class discussions expresses liberal political views. Lin disagrees with the classmates' views in many ways but refrains from speaking up in discussions, as he/she worries about being judged or isolated by classmates.
Which term best describes what shapes Lin's behavior?

A) Avant-garde
B) Fear of isolation
C) Dual climate of opinion
D) Opinion expression