A man is standing still in front of a swing. A child is seated on it and swinging. The child sounds a whistle that produces a note at a steady frequency. The man notes the frequency of the sound when the swing is at positions X, Y and Z. At which position will the man hear the greatest frequency?
- Awhen the swing is at X
- Bwhen the swing is at Y and moving away from the man
- Cwhen the swing is at Y and moving towards the man
- Dwhen the swing is at Z