All of the following statements are true about the normal distribution except
A. The total area under the normal curve is one.
B. Values located on the normal curve are not meant as actual observations.
C. The proportion of observations two standard deviations above the mean is the same as the proportion two standard deviations below the mean.
D. The normal distribution is a mathematical model of a population distribution.
E. The normal curve crosses the x-axis at z-scores above 3.0 and below -3.0.