Find the three cubic roots of -1

possible answers

a> cos π/3 + i sin π/3, cos 3π + i sin 3π , cos 2π/3 + i sin 2π/3

b> cos π/3 + i sin π/3, cos π + i sin π, cos 5π/3 + i sin 5π/3

c> cos π/2 + i sin π/2, cos π + i sin π, cos 5π/2 + i sin 5π/2

d> cos π/4 + i sin π/4, cos π + i sin π, cos 5π/4 + i sin 5π/4

Any help would be greatly appreciated

please show step by step!