Work, Energy and Power question for NEET / JEE Main (EAMCET 2013 (Engineering)), with solution

The work done by a force $\vec{F} = 2\hat{i} - \hat{j} - \hat{k}$ in moving an object from the origin to a point whose position vector is $\vec{r} = 3\hat{i} + 2\hat{j} - 5\hat{k}$ is