Aluminum Metal Is Refined in a Very Energy-Intensive Process from Bauxite

Aluminum metal is refined in a very energy-intensive process from bauxite ore using the Hall process, which requires electrolysis of aluminum oxide, Al₂O₃, in molten cryolite at more than 1,012°C. In an industrial electrolysis cell, 1,900 kg of aluminum oxide was reduced with a current of 1,500 amps. How long did it take to reduce all the reactant to aluminum metal?

A) 1,000 hr
B) 2,000 hr
C) 330 hr
D) 4,000 hr
E) 660 hr