Until the nineteenth Century, aluminium was almost as expensive as gold. The invention of an inexpensive way to extract this metal by a 22-year-old American made this metal inexpensive subsequently. The inventor was

Until the nineteenth Century, aluminium was almost as expensive as gol

1.	Until the nineteenth Century, aluminium was almost as expensive as gold. The invention of an inexpensive way to extract this metal by a 22-year-old American made this metal inexpensive subsequently. The inventor was
A.	Goldschmidt
B.	Mond
C.	Charles-Martin Hall
D.	Parkes
Answer» D. Parkes