Hello! This problem doesn't have much to do with subtraction. Therefore, A and B are eliminated. There was a multiplication error, but saving just $120.83 won't help, because the average is slightly more than that. Saving that amount will only give him $1,449.96, which is 4 cents short of $1,450. There will be some months he has to save $120.83 and others $120.84. The answer is D.