Assertion (A): Routh criterion is in terms of array formulation, which is more convenient to handle.Reason (R): This method is used to investigate the method of stability of higher order systems.

• A. Both A and R are true and R is correct explanation of A
• B. Both A and R are true and R is not correct explanation of A
• C. A is true but R is false
• D. A is False but R is true