Copper (II) Sulphate solution is

Copper sulphate, also known as copper (II) sulphate, is also known as blue vitriol, bluestone, cupric sulphate, chalcanthite, and Roman vitriol. Therefore, it should be clear why copper (II) sulphate solution appears blue. The molar mass of copper (II) sulphate is 143 61 g/mol and it has the chemical formula CuSO₄.

When hydrated, the solution resembles blue solid crystals, while when anhydrous, it resembles white solid crystals. By treating copper metal with hot, concentrated sulfuric acid or its oxides with diluted sulfuric acid, the copper sulphate is created or manufactured industrially. In laboratories, copper sulphate is recommended. Because copper sulphate is hydrated, it is a solid blue solution that is bound to water molecules. Usually, one molecule of copper sulphate is joined to five molecules of water. The most significant and often utilised copper compound is copper sulphate. Copper sulphate is utilised in a variety of industrial and commercial fields, including agriculture, the paint and coatings industry, electrical applications, the manufacture of other chemicals, and other industrial and commercial fields.

Because it absorbs light in the red portion of the spectrum, copper (II) sulphate solution is a light blue or cyan colour.

Hence, the correct option is (D).