The matching hypothesis is a theory about interpersonal relationships that states that people tend to mate with people who are similar in physical attractiveness. This theory argues that before mating, people assess themselves, establish their level of physical attractiveness and establish characteristics for potential partners who share this same level of attraction. So, the correct answer is C. Physical attractiveness.
The complete phrase is "The matching hypothesis suggests that people will form relationships with others who are similar in physical attractiveness"
