Extraction of aluminium can be understood by :

Electrolytric reduction of `Al_(2) O_(3)` :
Electrolysis : `Al_(2) O_(3) + Cryolite + CaF_(2)`
Cathode : Carbon inside the `Fe` container
Anode : Graphite rods.
The purpose of adding cryolite is.

Options

A. to decrease the electrical conductivity of pure aluminium
B. to lower the melting point of `AI_(2)O_(3)`
C. to remove the impurities as slag
D. to increase the `Al%` in the yield

Answer

B