Jack and Diane Have Been Dating and Living Together for Two

Jack and Diane have been dating and living together for two years. Jack always puts Diane's needs before his own, is very supportive of Diane, and devotes a great deal of time and energy to the relationship. Diane, on the other hand, focuses on her own needs and problems and does not exert a great deal of effort when it comes to the relationship. According to equity theorists,

A) Jack should feel underbenefited and upset about the nature of the relationship, whereas Diane will be content because her needs are being met at minimal cost to her.
B) Jack and Diane should be content with the relationship because people in an equity relationship do not keep track of costs and benefits.
C) Jack should feel underbenefited and upset about the nature of the relationship, and Diane should feel overbenefited and guilty.
D) Jack should feel content with the relationship because he knows he's working for his partner's happiness, but Diane will feel overbenefited and guilty.