Why should metal sulphides and carbonates be converted to metal oxides during the process of metal extraction?

• A
  Metal oxides are more stable than sulphides and carbonates.
• B
  It is easier to reduce metal oxides to pure metal than to reduce sulphides or carbonates.
• C
  Metal oxides are more reactive than sulphides and carbonates.
• D
  Metal oxides are easier to purify by electrolysis.