Consider the following statements:
Roasting is carried out to:
$(i)$ convert sulphide to oxide and sulphate
$(ii)$ remove water of hydration
$(iii)$ melt the ore
$(iv)$ remove arsenic and sulphur impurities
Of these statements:

• A
  $(i), (ii),$ and $(iii)$ are correct
• B
  $(i)$ and $(iv)$ are correct
• C
  $(i), (ii),$ and $(iv)$ are correct
• D
  $(ii), (iii),$ and $(iv)$ are correct