Reilly and Karissa Have Been Friends for Years

Reilly and Karissa have been friends for years. When they are together, they spend a lot of time catching up and sharing their feelings about recent events in their lives. However, when Reilly spends time with another friend, Andrew, she notices they spend more time bonding through activities such as mini-golfing and surfing, and they often flirt and make jokes of a sexual nature. These differences in Reilly's friendships illustrate the theory that

A) friendships differ by culture.
B) friendships are influenced by expectations.
C) friendships are usually stronger with peers.
D) friendships differ by sex.