An exam prep company states that students who take their prep course improve by an average of 8 points on a post test as compared to their pre-test score. Suppose the difference in score (post minus pre) for all students who take the prep course follows a normal distribution with a population mean difference of 8 points and a population standard deviation of 4 points. Also suppose the next prep course will be taken by 16 students which can be considered a random sample. Which graph best represents the model that could be used to approximate the probability that the resulting mean difference in scores (post minus pre) for the 16 students will exceed 10 points?