Elasticity is that property of the object by virtue of which it regain its original configuration after the removal of the deforming force.

The correct option is C $N{m}^{2}K{g}^{-2}$
Gravitational force: F

then,

G = $\frac{F{R}^2}{M_1{M}_2}$

unit of F = N
unit of mass = Kg
unit of R = m
unit of G = $N{m}^{2}k{g}^{-2}$

Work is dot product of two vectors. i.e. .
And dot product is a scalar quantity. Therefore, work is a scalar quantity. 

Work done is said to be one joule if one newton of  force displaces the body through a distance of one meter in the direction of applied  force .