A task force to encourage car pooling did a study of one-way commuting distances (in miles) of workers in the downtown Dallas area. A random sample of 60 of these workers was taken. The commuting distances of the workers in the sample are given in the following grouped frequency distribution: Class limit (distance in miles) Frequency 1 - 10 18 11 - 20 24 21 - 30 10 31 - 40 4 41 - 50 4 For this grouped frequency distribution, the modal class is A. 11 - 20 B. 21 - 30 C. 1 - 10 D. 41 - 50