Research has favored cooperative learning in cases where two essential conditions are met. First, there must be some kind of recognition or small reward provided to groups that do well so that group members can see that it is in their interest to help their group-mates learn. What is the second essential condition?

individual accountability

Explanation:

In this research, the second essential condition for cooperative learning would be individual accountability. This term refers to the belief that everyone will be accountable for his/her performance and learning. This ultimately prevents an individual's in a team from sitting back and letting the other members do all of the work and still reaping the benefits. Instead, each individual must contribute as much as possible towards the end goal of the team's project.

answer; /// i do believe that the correct answer is (d) majority vote as an approval requirement;