A small source of sound moves on a circle as shown in the figure and an observer is standing on \[O\]. Let \[{{n}_{1}},\ {{n}_{2}}\] and \[{{n}_{3}}\]be the frequencies heard when the source is at \[A,\ B\] and \[C\] respectively. Then [UPSEAT 2002]

• A.            \[{{n}_{1}}>{{n}_{2}}>{{n}_{3}}\]
• B.            \[{{n}_{2}}>{{n}_{3}}>{{n}_{1}}\]
• C.            \[{{n}_{1}}={{n}_{2}}>{{n}_{3}}\]
• D.            \[{{n}_{2}}>{{n}_{1}}>{{n}_{3}}\]