The direction of the magnetic force can be found by applying the right hand rule.
When using the right hand rule, your fingers point in the direction of the field, and the thumb points in the direction of the current. Whichever direction your palm is facing is the direction of the force (force is the cross product of the two vectors).
You can see that in this problem the current is traveling clockwise in the wire.
So for Part A,
the current is going from a to b, and so have your thumb point from a to b. Next point your fingers in the direction of the field, which is pointing upwards. Therefore your palm should be pointing in the positive x direction.
Similarily, the direction of torque can also be determined using the right hand rule. Since the torque is the cross product of Magnetic Moment (*which is current*area) and magnetic field.
So once again start by having the thumb point from the axis towards the current flow direction, in Part B this would be from origin to point b direction.
Next, point your fingers in the direction of force (*not field, since this is torque), force is in x direction.
And so your palm should be facing in the negative z direction, the direction of the torque.
Parts C and D can be solve similarily.
the answer is no, because the forces basicically cancel each other out.
Also No, same reason as part E.