You Are a Teacher Assigning Group Projects to Your Class

You are a teacher assigning group projects to your class, but you want to make sure each group member contributes equally. Which of the following would be the best strategy to prevent social loafing?

A) Allow the students to choose group members rather than assign students to groups
B) Assign students to groups rather than allow the students to choose group members
C) Grade each student on the performance of the group rather than individually
D) Assign students to groups based on their grades rather than randomly