单选题图所示结构A、B两点相对水平位移（以离开为正）为（　　）。<br/> <br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325532_0.png"><br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325532_0_1.png">