单选题图所示结构E为常数，在给定荷载作用下若使支座A反力为零，则应使（　　）。<br/> <br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325581_0.jpg"><br/> <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/8325581_0_1.png">