The contingency table below shows results from a study about whether there was an association between mobile phone use and eye cancer. Complete parts (a) through (c). Eye Cancer and Use of Mobile Phones Mobile Phones Cases Controls Yes 20 51 No 104 425 Total 124 476 a. Ine study was retrospective. Explain what inis means. A. The study followed subjects into the future to see if they developed cancer. B. The study followed subjects into the future to study their mobile phone use. C. The study is one in which subjects are asked to report on their past mobile phone use. O D. The study is one in which subjects are asked to report on their current mobile phone use. b. Explain what is meant by "cases" and "controls" in the heading of the table. A. Cases refer to subjects who had eye cancer, and controls refer to subjects who did not have eye cancer. B. Cases refer to subjects who did not have eye cancer, and controls refer to subjects who had eye cancer. O C. Cases refer to subjects who had eye cancer, and controls refer to mobile phone use. c. What proportion had used mobile phones, of those in the study who had eye cancer? The proportion is (Round to the nearest hundredth as needed.)