At a large hospital, the durations of emergency room visits, from check-in to discharge, are approximately normally distributed with a mean of 167 minutes and a standard deviation of 76 minutes. Which interval, to the nearest minute, contains the middle 80% of durations?
(A)15 minutes to 319 minutes (B)53 minutes to 281 minutes (C)70 minutes to 264 minutes (D)91 minutes to 243 minutes
C