Answer:
the sign of these carriers is POSITIVE
Explanation:
In the effect, he found the charge carriers that were subjected to two forces, one electric and the other magnetic.
F = F_e + F_m = q E + q v x B
bold indicates vectors
The electric field goes to the east, therefore the current also has this direction, the vector product of the velocity of the charge carriers towards the east and the magnetic field upwards, using the right hand rule a magnetic force is created towards the north if the carriers are positive.
In the exercise they indicate that the north side has a higher potential than the south side, therefore there must be an accumulation of carriers on this side that create an electric field (Hall) that is put to the magnetic force until reaching equilibrium when the total force is zero.
Therefore the sign of these carriers is POSITIVE