Remark
There is a very quick way to do this. Scan the numbers. You want 75 to be the mean, so make it so. Then figure out how many up or down you go from 75. I'll make a list of the givens.
72 - 3 72 is three down from 75 so call it - 3
75 0 That is your desired average so it adds nothing to the score.
74 -1 It is one down from 75, so call it -1
76 +1 It is one up from 75
76 +1 it is one up from 75
75 adds 0.
-3 - 1 + 1 + 1 = - 2
That comes - 2/7 which means that you need a score just under 75. So 75 will give you the right average of 75
Answer B <<<<<