单项选择题

用叠加原理做图示梁的弯矩图,则A、B、C截面的弯矩为()。

A.80kNm,108.75kNm,0
B.-80kNm,108.75kNm,0
C.80kNm,100.75kNm,0
D.-80kNm,100.75kNm,0