An electric motor works on the principle:

An electric motor is a machine that converts electrical energy into mechanical energy.  It is based on the principle that when a  conductor carrying an electric current is placed in a magnetic field, it is given a direction by Fleming's left-hand rule and receives a mechanical force whose  magnitude is given as follows. 
$F = B \times I \times L$where B is the Weber's magnetic field  per square meter, I is the ampere's current, and L is the metric coil length. Forces, currents, and  magnetic fields all point in different directions. As specified in Option A, electromagnetic induction is the process in which a conductor is placed in a specific position and the magnetic field is constantly changing, or the magnetic field is stationary and the conductor moves. This creates a voltage or EMF (electromotive force) between the conductors. Therefore, an electric motor operates on the principle that when a rectangular coil is placed in a magnetic field and an electric current flows, a force acts on the coil to continuously rotate the coil. Therefore, option B is correct.