The word "wrestle" in sentence 4, paragraph 3 could best be replaced by ______.

A．Most people develop relationships simply to enjoy a long life.
B．Rewarding human relationships are essential to life.
C．New relationships can be established on mutual interests.
D．Telling friends about their strengths will make them feel better about them- selves.

A．the impact of mutual interests
B．the establishment of relationships
C．the reinforcement of positive perceptions
D．the purpose of relationships