In Their Research on Differences Between Exchange and Communal Relationships

In their research on differences between exchange and communal relationships, Clark and Mills found that tit-for-tat reciprocation of favors

A) increased liking in intimate relationships, but created discomfort in more formal and less personal relationships.
B) increased liking in both communal relationships and in formal exchange relationships.
C) increased liking in more formal exchange relationships, but decreased liking in more intimate communal relationships.
D) was a major characteristic of long-term happily married couples.