一根电阻为R的导体横截面为A,长度为L,导体两端施加电压V,通过导体的电流为I,电导的正确计算公式为( )。
A <img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/22417252_0.png"> B
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/22417252_0_1.png"> C
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/22417252_0_2.png"> D
<img border="0" alt="" src="https://tuku.weimei168.com/uploads/upimg/20251103/22417252_0_3.png">