During lecture, Psy 1001 students saw an experiment in which participants were told either that they would experience intense and painful shocks or mild shocks that were not painful. Then, while waiting for the shock treatment, participants answered survey questions on whether they would like to spend time waiting alone or with another person. In this study, the questionnaire that students completed served __________________.Select one:a. as the independent variable.b. as the dependent variable.c. to randomly assign participants to groups.d. as experimental control.