Negate A , we get most of the discounted tickets are used.
if the price of the tickets still profitable after discounting, then the conclusion still holds true.
Thus, A is not assumption.

I find chinese people have difficulties about the tense of this question. However, native english speaker take it for granted. In Chinese thinking, we can reduce the amount that was allowed. After the reduction enact, the agreement has nothing to do with the new amount. Because its new and totally i...