Assertion (A): In centrifugal compressors, sometimes guide vanes are provided at inlet.
Reason (R): The guide vanes provide pre-whirl which helps in restricting the Mach number at inlet to an acceptable value, below supersonic.
(A) Both A and R are individually true and R is the correct explanation of A
(B) Both A and R are individually 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