In this problem, the classes can be written as winter, spring, summer, and fall. The expected frequencies can be calculated using Uniform distribution. Remember that when the data follows uniform distribution, all the outcome will equally likely. Therefore, all the outcomes on this problem, based on uniform distribution, have a probability of 0.25 since there are four seasons. The expected frequencies can be calculated by multiplying the sample size n with expected probabilities. Hence, the probability for each class is 200 x 0.25 = 50. The correct answer is E.