Assertion (A): Sultan Muhammad bin Tughlaq issued currency of copper coins and declared them as legal tender. Reason (R): Sultan's treasury was empty because of his short-sighted projects.

• A. oth A and R are true and R is the correct explanation of A
• B. oth A and R are true but R is not a correct explanation of A
• C. is true but R is false
• D. is false but R is true