Assertion (A): Hollow waveguides are frequently used as transmission lines at microwave frequencies.Reason (R): Waveguide has high power handling capacity, low loss and simple structure.

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