Mr. willis separates his students into four teams that each represent four different perspectives on a social issue. each group is to establish an argument supporting why their perspective is correct and then present the information to the class. after each group presents their perspective, mr. willis guides the class through a period of analyzing and questioning each perspective. which of the following types of collaborative learning approaches has mr. willis utilized? a. problem-centered instruction b. peer teaching c. cooperative learning d. both cooperative learning and problem-centered instruction