6. ^(*) The current in a metal wire of cross-sectional area 10^(-6)m^(2) is 1.6A .If the free electron density of the metal is 8times 10^(28)m^(-3) then the drift speed of electrons is (A) 1.25times10^(-3)ms^(-1) (B) 2times10^(-3)ms^(-1) (C) 1.25times10^(-4)ms^(-1) (D) 2times10^(-4)ms^(-1)