IPO A program that was intended to cure a person's fear of spiders was offered at a local zoo. Volunteers with a fear of spiders participated in the program, which included holding a spider for 15 minutes. One month after they completed the program, the participants were contacted and surveyed about the program. Over 90 percent of the participants claimed they were cured of their fear of spiders. Based on the description of the program, which of the following statements is true? a. Because over 90% of the participants claimed to be cured, the results prove that holding a spider will cure a person's fear of spiders. b. Because over 90% of the participants claimed to be cured, the results can be generalized to the population of all people who have a fear of spiders. c. Because the participants were volunteers, the study is a census of all people in the local area who have a fear of spiders. d. Because the participants were self-selected, a person's desire to be cured could be a confounding variable. e. Because participants held a spider for 15 minutes, the study is an experiment and the results can be generalized to the population of all people who have a fear of spiders