Title: Colourless Aqueous Solution

There are various types of aqueous solutions that can be coloured or colourless. The answer to the given question is option 'D' which states that both ZnSO4 and Al2(SO4)3 are colourless. Let us understand the reason behind this.

Aqueous Solution:
An aqueous solution is a solution in which water acts as a solvent. It is a homogeneous mixture of one or more substances (called solutes) dissolved in water (called the solvent). The solute can be a solid, liquid, or gas.

Colourless Aqueous Solution:
A colourless aqueous solution is a solution that does not have any colour. The absence of colour in a solution indicates that the solute does not absorb any visible light, or absorbs light in a way that does not result in the perception of colour.

FeSO4:
Iron(II) sulfate or ferrous sulfate, commonly known as FeSO4, is a salt with the formula FeSO4. It is a greenish or yellowish crystalline solid, and its aqueous solution is light green. Hence, FeSO4 is not a colourless aqueous solution.

ZnSO4:
Zinc sulfate or ZnSO4 is a colourless crystalline solid. Its aqueous solution is also colourless. The reason behind this is that the Zn2+ ion does not have any unpaired electrons in its d-orbital, which means it does not absorb light in the visible region. Hence, ZnSO4 is a colourless aqueous solution.

Al2(SO4)3:
Aluminum sulfate or Al2(SO4)3 is a white crystalline solid. Its aqueous solution is also colourless. The reason behind this is that the Al3+ ion does not have any unpaired electrons in its d-orbital, which means it does not absorb light in the visible region. Hence, Al2(SO4)3 is a colourless aqueous solution.

Conclusion:
From the above discussion, we can conclude that FeSO4 is not a colourless aqueous solution, while ZnSO4 and Al2(SO4)3 are colourless aqueous solutions.