The Al₂O₃ content of cryolite in Hall-Heroult's cell is maintained between

A. electrolytic reduction of TiCl₄ B. calcium reduction of TiCl₄ C. magnesium reduction of TiCl₄ D. thermal dissociation of TiCl₄

A. Both A and R are correct, but R is not the correct reason for A B. Both A and R are false C. Both A and R are correct and R is the correct reason for A D. A is true but R is false

A. Atomic number: 30, Atomic weight: 65.38 B. Density: 7.13 gm/cm³ C. Melting point: 419.5°C, Boiling point: 910°C D. All are correct

A. P-2, Q-3, R-4, S-1 B. P-4, Q-2, R-3, S-1 C. P-3, Q-4, R-2, S-1 D. P-1, Q-3, R-2, S-4