ANS:D - both(b) & (c).

(b) and (c) states: (b) - "keep the electrolyte in liquid condition by the generation of heat." (c) - "electrolytically dissociate alumina." In the process of electrolytic reduction of alumina to aluminum in a carbon-lined furnace, both options (b) and (c) are correct: (b) - The generation of heat by the electric current helps maintain the alumina (Al2O3) in a molten or liquid state. The furnace operates at temperatures between 800-900°C, and the electric current passing through the carbon lining generates enough heat to keep the alumina melted. This molten alumina serves as the electrolyte in the electrolytic reduction process. (c) - The primary purpose of supplying electric current to the furnace is indeed to electrolytically dissociate alumina. The electric current provides the necessary energy to break the chemical bonds in alumina, allowing the aluminum ions to migrate towards the cathode (negative electrode), where they gain electrons and deposit as molten aluminum metal. Meanwhile, oxygen ions move towards the anode (positive electrode), release electrons, and form gaseous oxygen. Therefore, both options (b) and (c) are correct explanations for the function of the electric current in the electrolytic reduction cell used for converting calcined Al2O3 to aluminum.