Eight charges each of value q are placed on a ring of radius R placed in x - y plane with origin at centre . A - q charge having mass m is projected from `z=oo` towards the centre of the ring with velocity v . The velocity of - q when it reaches the centre of ring is (neglect gravity)

Options

A. `sqrt((8kq^2)/(mR))`
B. `sqrt((8kq^2)/(mR)+v)`
C. `sqrt((16kq^2)/(mR)+v^2)`
D. `sqrt((16kq^2)/(mR)+v)`

Answer

C