Problem: Consider the following proposed relationships between an independent and a dependent variable. In each case, would it be realistic for a researcher to perform an experiment to test the theory? If yes, briefly describe what would be randomly assigned in the experiment; if no, briefly explain why not. (a) An individual's level of religiosity (X) and his or her preferences for different political candidates (Y). (b) Exposure to negative political news (X) and political apathy (Y). (c) Military service (X) and attitudes toward foreign policy (Y). (d) A speaker's personal characteristics (X) and persuasiveness (Y).