Since all the lists are in order, the median is easy to find, and it is the same in all cases: 3.

Also, since they all have five members, we don't have to compute the actual mean but just compare the sum of the lists. Any sums that are less than 15 (because 15/5 = 3) would fit the description of having an average less than the median. (To save time, don't calculate all the sums as I've done here, but instead start adding from the back of the list then stop once you hit 15.)

The sums are 13, 17, 15, 15, 14, and 19. Therefore, A and E are the answers.