弹性受弯时,工字钢截面正应力分布图正确的是( )。
A <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/23425111_0_1.png"> B
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/23425111_0_2.png"> C
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/23425111_0_3.png"> D
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251122/23425111_0_4.png">