Suppose 4-year-olds in a certain country average 3 hours a day unsupervised and that most of the unsupervised children live in rural areas, considered safe. Suppose that the standard deviation is 1.8 hours and the amount of time spent alone is normally distributed. We randomly survey one 4-year-old living in a rural area. We are interested in the amount of time the child spends alone per day.

In words, define the random variable X.

(A) the number of people that live in rural areas
(B) the time (in hours) a 4-year-old spends unsupervised per week
(C) the number of 4-year-old children that live in rural areas
(D) the time (in hours) a child spends unsupervised per day
(E) the time (in hours) a 4-year-old spends unsupervised per day