NEET 2021 Model Test Paper 6

The major role of fluorspar (CaF2) which is added in small quantity in the electrolytic reduction of alumina dissolved in fused cryolite (Na3AlF6) is :-
(a) as a catalyst
(b) to make the fused mixture very conducting
(c) to lower the temperature of melting
(d) to decrease the rate of oxidation of carbon at the anode