单项选择题

某圆柱杆件如图所示,受力作用,其中F=100KN,AB段截面直径D=200CM2,BC段截面D=100CM2,求截面1-1,2-2的应力分别为()

A.-5MPa,10MPa
B.5MPa, -10MPa
C.-5MPa,-10MPa
D.5MPa,10MPa