Test A
Stereotyping consists of assigning traits to people solely on the basis of a category. Some researchers suggest that stereotyping has four clear phases. First, a person distinguishes some category of people, for example, economists. Second, the person notes that one or more of the people in this category have certain traits, for example, dullness. Third, the person generalizes that everyone in this category has these characteristics, for example , that all economists are dull. Finally, when meeting someone the person is not acquainted with but knows to be, for example, an economist, the person stereotypes this individual as dull. 
In general, the major supporting details of this paragraph are
A、A. Characteristics given to people solely on the basis of their class or category.
B、B. People who have studied stereotypes.
C、C. Examples of stereotypes.
D、D. The stages people go through when they stereotype.