Groupthink can be prevented by a leader who

A) is directive and makes his or her own position clear from the start.
B) invites outside experts to critique a group's developing plans.
C) tries to maintain high morale among group members.
D) emphasizes the importance of the issue under discussion.

Inviting outside experts to critique a group's developing plans can bring in fresh perspectives, challenge assumptions, and prevent the group from becoming too internally focused and resistant to alternative viewpoints, which can contribute to groupthink. A leader who is directive and makes his or her own position clear from the start may stifle dissenting opinions and contribute to a conformity pressure, which can lead to groupthink. Trying to maintain high morale among group members and emphasizing the importance of the issue under discussion may be important for group cohesion and motivation, but they do not directly address the root causes of groupthink.