Auto-reduction process is used for the extraction of :

Self-reduction method which is also known as auto-reduction method .The sulphide ore are heated in the air and a part of these is changed into oxide or sulphate then that reacts with the remaining part of the sulphide ore to give its metal.

This method is used for less electropositive metals i.e. Hg, Pb,Cu ,Sb.

Hence, correct option is (A),(B) and (C).