A source emits a sound of frequency of 400 Hz, but the listener hears it to be 390 Hz. Then 

(1) The listener is moving towards the source

(2) The source is moving towards the listener

(3) The listener is moving away from the source

(4) The listener has a defective ear

(3) Since apparent frequency is lesser than the actual frequency, hence the relative separation between source and listener should be increasing.

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