A point charge q moves from point P to pont S along the path PQRS (fig.) in a uniform electric field E pointing parallel to the poistive direction of the X-axis. The coordinates of the points P, Q, R and S are(a, b, O), (2a, O, O)(a, -b,`ulO`) and `(O, O, O) respectively. The work done by the field in the above process is given by the expresison............
A. `q a E`
B. `-q a E`
C. `q[sqrta^(2) + b^(2)]E`
D. `3qE sqrt((a^(2) + b^(2)))`
