unusual problem, i`ll try but not sure in my answer
median number score of 73 scores will be 37, so the table ca be rewritten like that
50-59-2
60-69-12 (2+10)
70-79-28 ( 2+10+16)
80-89-55 (2+10+16+27)
90-99-73 (2+10+16+27+18)
median score falls into 80-89 interval, my answer is D
wait OA-?

Nice work, Clock! I'd even look at it this way:

The sum of the first three categories is 28, so there are 28 data points in the first 3, and we need to find where the middle point is. Are there more than 28 in the higher categories? There are 18 in the highest and 27 in group "D", so if we take 10 from group D there are now:

28 below group D
28 in group D and above
17 in group D

Since we can get an equal number on either side of group D, the middle number has to be within group D.

Because the "middle number" just needs to have an equal number of values on either side of it, I think you can do this one pretty conceptually without having to even do much math...