Let r and θ respectively be the modulus and amplitude of the complex number z=2−i(2tan 5π/8 ), then (r,θ) is equal to
(1) (2sec 3π/8 , 3π/8 )
(2) (2sec 3π/8 , 5π/8 )
(3) (2sec 5π/8 , 3π/8 )
(4) (2sec 11π/8 , 11π/8 )