`CuSO_(4).5H_(2)O`, a hydrated salt, is a coordination compound of `Cu^(2+)` ions with `H_(2)O` molecules as the ligands. It can also be regarded as a solution of
A. solution of solid in a liquid
B. solution of liquid in a solid
C. salt of `CuSO_(4)` and water
D. co-ordination compound of copper sulphate with water molecules