Yves Is Called on in Class to Define the Representativeness

Yves is called on in class to define the representativeness heuristic. He answers that "it is a rule of thumb in which stimuli similar to an exemplar are believed to be more likely than stimuli that are dissimilar." Which part of his definition is incorrect?

A) a rule of thumb
B) similar to an exemplar
C) believed to be more likely
D) stimuli that are dissimilar