Positive intergroup contact can effectively reduce prejudice through a. avoiding contact with outgroup members until necessary b. imagined positive interactions with outgroup members c. competitive exercises with outgroup members d. testing positive interactions under adverse conditions

I believe the answer is: testing positive interactions under adverse conditions

Positive intergroup is characterized by these four components:  equal status, cooperative attitude between its members, same goals, and support by institutional and social authorities. All the factors above would help each members to see each other as an important part of society and would most likely to reduce prejudice among them.

1190 is your answer! the way you get it is 1400 - 15% =1190 : )