The answer is D because if you add all the same terms you get the answer
He could only make one team, considering that if you do 12-9, you are left with 3, and Jason wants to have his team consisted of 9 players. However, if you make 3 teams with 4 players on each team, or 4 teams with 3 players on each team, you could do that as well.
-48 is the answer to the question
mean = Summation of Data/Number of Data Added
mean = [(-54)+(-32)+(-70)+(-25)+(-65)+(-42)] / 6
mean = -288 / 6
mean = -48