Use the Normal to Model the Distribution of Sample Proportions

Use the Normal to model the distribution of sample proportions.
-The owner of a small convenience store is trying to decide whether to discontinue
Selling magazines. He suspects that only 5% of the customers buy magazines and thinks
That he might be able to sell something more profitable. Before making a final decision,
He keeps track of the number of customers who buy magazines on a given day. In a
Typical day his store has 280 customers. Which of the following statements is (are) true
About the sampling distribution of the sample proportion of customers who buy specialty
Clothes for their pets at this store?

A) The sampling distribution can be described a Normal model.
B) The mean of the sampling distribution is 0.05.
C) The standard deviation of the sampling distribution is 0.013.
D) All of the above.
E) None of the above.