Question 2. A 5-year prospective cohort study has just been completed. The study was designed to assess the association between supplemental vitamin A exposure and mortality and morbidity for measles. The relative risk (RR) for the association between vitamin A exposure and incidence of measles was 0.40 and the RR for measles mortality was 0.65. Which of the following statements is correct? Choose the ONE best answer. A. A cohort study is not an appropriate study design in this case because the association between one exposure and two different outcomes is being considered. B. One of the problems that this study may have faced is individuals being lost to follow-up during the five-year period. C. A cohort study is not a good design to study this association because measles is a very common disease. D. All of the above E. None of the above Question 3. Regarding the relative risks reported above, which of the following statements is correct? Choose the ONE best answer. A. Exposure to vitamin A appears to have a weak inverse association with incidence and a moderate inverse association with mortality for measles. B. Exposure to vitamin A appears to have a moderate inverse association with incidence and a moderate inverse association with mortality for measles. C. Exposure to vitamin A appears to have a strong inverse association with incidence and a moderate positive association with mortality for measles. D. Exposure to vitamin A appears to have a strong inverse association with incidence and a moderate inverse association with mortality for measles. E. Exposure to vitamin A have a strong inverse association with incidence and a strong inverse association with mortality for measles. .