Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A): Transducer should be placed perfectly parallel to the blood flow to get an insonation angle of 0 to 180 degrees, at the time of Doppler ultrasonography.
Reason (R): At an insonation angle of 0 to 180 degrees, the transducer receives maximum Doppler's shift from the blood flow.
In light of the above statements, choose the most appropriate answer from the options given below.