A body of mass 10 kg is moved parallel to the ground, through a distance of 2 m. The work done against gravitational force is : 

zero

gravitational force   works perpendicular to ground 

A body of mass 10 kg is moved parallel to the ground,

Hence Horizontal movement only

While gravitational force  acts perpendicularly

Hence No work is done against gravitational force   

No work is done against gravitational force