A proton beam passes without deviation through a region of space. This space has uniform transverse mutually perpendicular electric and magnetic fields with `E=220 kV'/'m and B = 50 mT`. The velocity of the beam is
Options:
(a) `4.4 xx 10^6` m/s
(b) `2.2 xx10^6` m/s
(c) `4 xx 10^6` m/s
(d) `2 xx 10^6` m/s