Barbie and Ken are in a relationship in which they share goals, have similar interests, support each other's dreams and decision making and share their possessions. Raquelle and Blaine, on the other hand, are in a relationship in which Raquelle makes all the decisions, spends all the money, and Blaine is very stingy with his possessions. In the end, Barbie and Ken's relationship last longer and they are happier. Which social psychological concept describes why Barbie and Ken's relationship is more successful than that of Raquelle and Blaine?

A) equity

B) altruism

C) proximity

D) companionate love

E) physical attractiveness