The unique geography of the United States has historically encouraged isolation

Research with nonmanipulated independent variables

A) cannot be conducted. B) usually has organismic variables for independent variables. C) is best done within an experimental design. D) can answer questions about causal relationships between variables.

In experimental research, the variable designated as the dependent variable

A) always refers to an organismic variable. B) is not directly manipulated by the experimenter. C) is merely another term for the organismic variable. D) is directly manipulated by the experimenter.