To determine which ore has sulphide-based minerals as its major component, let's examine each option:
Based on the chemical compositions of the options, only Sphalerite is a sulphide-based mineral. Therefore, the correct answer is Sphalerite.
Thus, the major component of the ore Sphalerite is a sulphide-based mineral, represented by the chemical formula ZnS.
Study the reaction scheme shown below and identify the reactants A, B and C. 
Study the reaction given below and answer the questions that follow:
NaNO₃ + H₂SO₄ → NaHSO₄ + HNO₃ (below 200°C)
(a) Give one reason for maintaining the temperature below 200°C.
(b) Why is concentrated Sulphuric acid used in the above reaction?