The correct options are
A E=0,B≠0
B E=0,B=0
C E≠0,B≠0
If A charged particle moves in a gravity-free space without change in velocity, then
(1) Particle can move with constant velocity in any direction, so B=0,E=0
(2) Particle can move in a circle with constant speed. Magnetic force will provide the centripetal force that causes particle is move in a circle.
(3) If qE=qvB and Magnetic & Electric force in opposite direction in this case also particle move with uniform speed.