Assertion (A): A complicated waveform can be replaced by sum or difference of two or more waveforms.Reason (R): The method of superposition is applicable only to linear 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 the correct explanation of A
• C. A is true but R is false
• D. A is false but R is true