Determine whether the given description corresponds to an observational study or an experiment. In a study of 420 men with a particular disease, the subjects were injected with vitamins to determine if the vitamins have an effect on the disease. Does the given description correspond to an observational study or an experiment? O A. The given description corresponds to an experiment. > O B. The given description corresponds to an observational study. O C. The given description does not provide enough information to answer this