A student by mistake mixed iron filings and sulphur powder. He wanted to separate them from each other. The method he should use is to dissolve the mixture in :

(a) boiling water

(b) cold water

(c) carbon disulphide

(d) kerosene

Iron fillings can be separated form the Sulphur, by either rolling a magnet over the mixture. The iron fillings will be attracted by the magnet. 

Or to the mixture containing sulphur and iron fillings add carbon disulphide, this will dissolve sulphur, leaving behind iron fillings.

Therefore the correct option is (c.) carbon disulphide.