An oil drop of radius r and density `rho` is held stationary in a uniform vertically upwards electric field 'E'. If `rho_0 (< rho)` is the density of air and e is quanta of charge, then the drop

Question

An oil drop of radius r and density `rho` is held stationary in a uniform vertically upwards electric field 'E'. If `rho_0 (< rho)` is the density of air and e is quanta of charge, then the drop has–

Options:
(a) `(4pir^3 (rho-rho_0)g)/(3eE)` excess electrons
(b) `(4pir^3 (rho-rho_0)g)/(eE)` excess electrons
(c) deficiency of `(4pir^3 (rho-rho_0)g)/(3eE)` elections
(d) deficiency of `(4pir^3 (rho-rho_0)g)/(eE)` electrons