While on vacation, malakai, a black athlete, went to a local restaurant for lunch. before he could sit down, the owner of the restaurant came out from behind the counter and told malakai to leave the restaurant because of his skin color. this scenario is an example of

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?