Three charges+ 2q, +3q and -4q are situated at (0, -3a), (2a, 0) and (-2a, 0) respectively in the x y plane. The resultant dipole moment about origin is ___ .

A

$$2qa(3\widehat{j}-7\widehat{i})$$

B

$$2qa(7\widehat{i}-3\widehat{j})$$

C

$$2qa(3\widehat{i}-7\widehat{j})$$

D

$$2qa(3\widehat{j}-\widehat{i})$$