When Public Schools Were Desegregated, People Thought That Simply Having

When public schools were desegregated, people thought that simply having black and white students attend school together would reduce stereotypes and prejudice.Given what you know about intergroup contact, why did this approach fail?

A) The groups were too different for students to find common similarities.
B) Contact alone could not overcome existing hostility.
C) Contact can work to reduce some outgroup bias, but not for racial differences.
D) Disparities between the groups deepened existing hostilities.