Research on Prejudices (Racism, Sexism, and So Forth) Has Demonstrated

Research on prejudices (racism, sexism, and so forth) has demonstrated that

A) once people are made aware of their prejudices, they tend to go away.
B) prejudice usually disappears when adolescents enter adulthood.
C) even well-meaning people who are doing their best to avoid and overcome prejudice show evidence of prejudice that may be operating at an unconscious level.
D) most people know rather exactly which prejudices they hold, and can take steps to prevent them from appearing in their behavior.