The head circumference of adult American males is normally distributed with mean 22.4 inches and standard deviation 2.1 inches. In order for a size "medium" cap to accommodate the middle 75% of all head circumferences, the minimum middle range of circumferences that the cap must fit is about: (a) (19.7, 25.1) (b) (21.0, 23.8) (c) (17.3, 27.5) (d) (21.5, 23.3) (e) (20.0,24.8]