A source of sound S emitting waves of frequency $100 \;Hz$ and an observer O are located at some distance from each other. The source is moving with a speed of $19.4 ms^{-1}$ at an angle of $60^{A^°}$ with the source observer line as shown in the figure. The observer is at rest. The apparent frequency observed by the observer (velocity of sound in air $330 ms^{-1}$), is : <br>

Question

( A ) 97 Hz
( B ) 100 Hz
( C ) 106 Hz
( D ) 103 Hz