Correct Answer - A
Work done `W = 3 xx 10^(-6) (V_(A) - V_(B))`, where
`V_(A) = 10^(10) [((5 xx 10^(-6)))/(15 xx 10^(-2)) + (2 xx 10^(-6))/(5xx10^(-2))] = (1)/(15) xx 10^(6)` volt
and `V_(B) = 10^(10) [((2xx 10^(-6)))/(15 xx 10^(-2)) + (5 xx 10^(-6))/(5xx10^(-2))] = - (13)/(15) xx 10^(6)` volt
`:.W = 3 xx 10^(-6) [(1)/(15) xx 10^(6) - (-(13)/(15) xx 10^(6))] = 2.8 J`