Answer:
B) Collecting and evaluating only information that supports their opinions
Step-by-step explanation:
Groupthink is a group phenomenon happening when group members' desire for cohesiveness becomes stronger than the critical approach of each member. Decisions that are affected by groupthink become biased and lack arguments which are essential for constructive discussion and effective decision-making.
In order to avoid this group problem, it is good to encourage team diversity (team members with diverse backgrounds and knowledge) and open discussion, where each team member would be backed up with arguments that supports his/her opinion. This is the best way to boost critical discussion and avoid groupthink, which leads to good team decisions.