The Most Frequent Reason Stated by the Respondents for Why

The most frequent reason stated by the respondents for why the scenario presented was actually an act of infidelity is

A) that the flirtation level was so high that it acted as a sexual turn-on to both parties.
B) that one should not be in any type of romantic relationship with more than one person.
C) there is a sexual double standard here, where men can get away with flirting and women cannot.
D) that the couple actually met in person.