Answer: D. random continuous variable
A normal distribution has its center at the mean and its spread is determined by the standard deviation. For the standard normal distribution, its mean is 0 and standard deviation is 1. It is in the shape of a bell curve. Most of the values fall in or around 0, forming the peak around this area. As you move away from 0, the values are less frequent which explains the drop-off. The distribution is continuous as you can have any real number (decimal or whole). It's also random because of the nature of statistics.