You Strongly Disagree with the Course of Action Your Group

You strongly disagree with the course of action your group has decided on but when you speak up in the first meeting, you are hushed. Your group never explores alternate plans or attempts to identify flaws in the plan they have chosen. After being hushed, you don't feel that you can express your dissent, and even if you do, it won't matter because you're sure you won't be heard. The group seems to be suffering from ________.

A) The fallacy of principle belief
B) Poor communication
C) Groupthink
D) Primary choice favoritism