Final answer:
The manipulated variable in a comedy experiment is the 'Type of comedy', which is the factor that the researcher intentionally changes to observe effects on the outcome, making it the independent variable.
Step-by-step explanation:
In designing a comedy experiment, the manipulated variable is the factor that the researcher changes or controls in order to examine its effect on the outcome. In the list you provided, the manipulated variable would be c. Type of comedy. This is because it is the aspect of the experiment that the experimenter can change to observe how it affects the audience's reactions. The dinner theatre location, audience demographics, and performer's confidence would be considered controlled variables or demographics that are not actively being changed by the experimenter for the purpose of the study.
Furthermore, the manipulated variable is synonymous with the independent variable, which is what is controlled by the experimenter to observe effects on the dependent variable, which would be the audience reaction in this case. Therefore, altering the type of comedy should demonstrate changes in the dependent variable, helping the experimenter understand the comedic preferences or responses of different audiences.