Answer:
a. One has a friend who is a member of that minority group.
Step-by-step explanation:
The correct answer is option "a" because having a friend who is part of a minority group makes the person that is not part of the minority group getting more involve in the group and understanding the problems and situations the group lives every day in a more deeply way.
If you do not know anyone that is part of a minority group you never 'get in touch' with the problems and situations the group lives and you never 'put yourself in their shoes', you are more likely to ignore what is happening with the minority group.