What Is the Effect of Shared Social Group Membership on Emotion

What is the effect of shared social group membership on emotion perception?

A) People engage in more facial mimicry with members of other groups than members of their own social groups
B) Although people have more daily exposure to the expressions of their ingroup members compared to non-group members, there is no documented difference in emotion recognition accuracy between social groups
C) Observers tend to be slightly more accurate in recognizing the emotion expressions of their own group members compared to the expressions of people not in their group
D) Both A and C are true