An electron (mass =9.1×10⁻³¹ ; charge =−1.6×10⁻¹⁹ C) experiences no deflection if subjected to an electric field of 3.2×10⁵ V/m and a magnetic field of 2.0×10⁻³ Wb/m². Both the fields are normal to the path of electron and to each other. Ifthe electric field is removed, then the electron will revolve in an orbit of radius :
a. 45 m
b. 4.5 m
c. 0.45 m
d. 0.045