9、例如,在(500,0.30;100,0.40;-50,0.30) 和(500,0.30;150,0.40;-100,0.30)中选择,我们可以通过抵消化简成(    )与(   )的比较

A (100,0.40;-50,0.30)

B (50,0.40;-100,0.30)

C (150,0.40;-200,0.30)

D (150,0.40;-100,0.30)