In general, which of the following is NOT a common source of conflict between friends?

a. gangs and cliques

b. envy and jealousy

c. developing common interests

d. anger

I would go with letter c. developing a common interest. When people have more in common, the less likely they would have any conflict. Conflicts arise because we have different views and goals this can clash with others who have the opposite view. If we have more things in common the less likely there will be conflict.