The residents of Town X participated in a survey to determine the number of hours per week each resident spent watching television.The distribution of the results of the survey had a mean of 21 hours and a standard deviation of 6 hours.The number of hours that Pat, a resident of Town X, watched television last week was between 1 and 2 standard deviations below the mean.Which of the following could be the number of hours that Pat watched television last week?