7. Suppose a study investigated the effects of vitamin A, vitamin C, and omega-3 fatty acids supplements on improving eye health and vision. 300 adults volunteered to take part in the study. In the study, participants were randomly assigned to one of 3 different levels of Vitamin A (Level A, Level B, or Level C) and randomly assigned to one of 2 different levels of Vitamin C (Level 1 or Level 2) and randomly assigned to one of 2 different levels of omega-3 fatty acid (Level I or Level II). a. Identify the subjects of the study. b. Identify the factor(s) for the study and the number of treatment level(s) for each factor. c. How many different treatment groups are there in this study