Assertion(A): Catalysts are always transition metals.
Reason(R): Transition metals have variable oxidation state.

Options

A. If both (A) and (R) are true and (R) is the correct explanation of (A).
B. If both (A) and (R) are true but (R) is not the correct explanation of (A).
C. If (A) is correct but (R) is incorrect.
D. If (A) and (R) are both incorrect.

Answer

B