Which of the following dimensional formula is incorrect

Options

A. [permittivity of the free space `xx` electric field] `= M^(0)L^(-2)T^(1) A^(1)`]
B. [electrical conductivity] `= M^(-1) L^(-3) T^(3)A^(1)`]
C. [viscous force] `= [M^(1)L^(1)T^(-2)]`
D. `[("Electric field")/("Magnetic field")]=[M^(0)L^(1)T^(-1)]`

Answer

B