What were new opportunities for african americans in the field of education? (choose all that apply.) a. african americans became presidents and leaders of black colleges. b. african american graduate schools developed. c. african american women were allowed an education. d. african americans were allowed to attend schools with white students. me i will give brainliest

Martha participates in a research study in order to receive extra credit for her psychology class. when she arrives in the research office she is given a can of what looks and tastes like beer, but which actually contains no alcohol. in the adjoining room martha's classmate karen is also participating in the study. karen receives a can of alcoholic beer. if the experiment was designed to test the effects of alcohol on concentration, then who is exposed to the independent variable?