Answer:
Distinctiveness.
Explanation:
As the exercise exemplifies, Michelle is most likely relying on distinctiveness information in order to explain her brother's behavior. This is due to the fact that distinctiveness focuses on what makes something different or unique, distinct from other things. If Mark generally does not like chocolate, it is fair to assume that if he is eating one it's because it's really tasty. Therefore, even if it's chocolate (something he would not eat) it has to be different from other types of chocolate he has eaten before.
