单项选择题

如图所示;用游标深度尺测得55°的燕尾槽的深度是40mm,用直径为30mm的圆棒做测量棒,测得两圆棒之间的距离为20.40mm,求燕尾槽槽底A和槽口B的宽度()。

A.102.36mm,56.17mm
B.115.40mm,53.80mm
C.77.60mm,48.20mm
D.108.03mm,52.02mm