The correct option is A FeSO4
The colour of hydrated Fe2+ ion is green. Thus, when FeSO4 is added to water, the Fe ions get hydrated and the solution turns green. This is why, FeSO4 is commonly known as green vitriol.
Similarly, Cu2+(aq) is blue in colour, and thus CuSO4 is known as blue vitriol.
ZnSO4 solution is colourless as Zn2+ is colourless.