Given below are two statements, one labelled as Assertion (A) and the other labelled as Reason (R).
Assertion (A): Transformer is useful for stepping up or stepping down voltages.
Reason (R): Transformer is a device used in D.C. circuits.
In the context of the above two statements, which one of the following is correct?

A. Both (A) and (R) are true and (R) is the correct explanation of (A)

B. Both (A) and (R) are true, but (R) is not the correct explanation of (A)

C. (A) is true, but (R) is false

D. (A) is false, but (R) is true

Answer: Option C