The work done in terms of the force and displacement is,
where F is the force and d is the displacement,
The labourer is moving along the horizontal path with the constant speed, thus, no force must be acting on the labourer along the horizontal direction.
The work done in the horizontal direction is zero.
As there is a gravitational force acting on the load supported by the labourer but the load remains in its same position. Thus, no displacement of the load takes place.
The work done on the load is also zero (in the vertical direction).
Hence, option B is the correct answer (no work is done in the given case).