A force \[\overrightarrow{F}=-K(y\hat{i}+x\hat{j})\] (where K is a positive constant) acts on a particle moving in the x-y plane. Starting from the origin, the particle is taken along the positive x- axis to the point (a, 0) and then parallel to the y-axis to the point (a, a). The total work done by the forces \[\overrightarrow{F}\] on the particle is [IIT-JEE 1998]

• A.             \[-2\,K{{a}^{2}}\]
• B.                                         \[2\,K{{a}^{2}}\]
• C.             \[-K{{a}^{2}}\]                      
• D.             \[K{{a}^{2}}\]