Which of the following is not an ore of aluminium?

The correct option is C Kernite
Answer:- (C) Kernite

Kernite is an ore of Boron having chemical formula $N{a}_2{B}_4{O}_7.4H_{2}O$.

Bauxite - $A{l}_2{O}_3.2H_{2}O$

Cryolite - $N{a}_{3}Al{F}_6$
Corundum - $A{l}_2{O}_3$(anhydrous)