Which expert shows the clearest example of the pathos

The prefix of the italicized word in the sentence is rather difficult

How can you avoid the problem of groupthink? a. by choosing a group leader to direct the group b. by composing the team of only like-minded individuals c. by encouraging all members to voice their opinions d. by keeping quiet when you disagree with another group member's opinion

Which form does a verb take when the subject receives the action?