If force is expressed in Newton and the distance in metre, then the work done is expressed in

Joule
Kg wt m
Kg wt
Watt

The correct answer is A. Joule.

Work is the product of force and distance. Force is measured in Newtons (N), and distance is measured in meters (m). Therefore, work is measured in Joules (J), which are defined as Newton-meters (N m).

Option B, Kg wt m, is not a valid unit of work. Option C, Kg wt, is a unit of mass, not work. Option D, Watt, is a unit of power, not work.