Which of the following statements isn't a property of the normal probability distribution? Please explain briefly why

A. The normal distribution is symmetric

B. Exactly 90% of all possible observed values of the random variable x are within plus or minus two standard deviations of the population mean

C. The mean, median and mode are equal

D. The area under the normal curve to the right of the mean is equal to the area under the normal curve to the left of the mean

E. All of the above answers are properties of the normal distribution.