Correct Answer - A::C
(a,c) Froth floating process is used to extract metal from sulphide ore. This method utilise collectors and depressants whose functions are as follows
(i) Collectors enhance the non-wettability of the mineral particles.
(ii) By using depressants in the process two suphide ores can be separated e.g. , sodium cyanide is used as a depressant to separate lead ore from zinc sulphide ore.