Answer:
force is -y direction
Step-by-step explanation:
The magnetic force is given by the equation
F = q v x B
where bold letters indicate vectors.
The direction of this force can be found by the right-hand rule, where the thumb points in the direction of speed, the other fingers extend in the direction of the magnetic field and the palm is in the direction of force for a positive charge
let's apply this to our case
the speed is in the direction + x the thumb
the magnetic field in the + z direction fingers extended
the palm is in the direction - y
force is -y direction