电路如图所示,其中A1、A2、A3、A4均为理想运放,输出电压u0与输入电压u11、u12的关系式为( )。
A A.<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24214919_0_1.png"> B
B.<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24214919_0_2.png"> C
C.<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24214919_0_3.png"> D
D.<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/24214919_0_4.png">