Acoustic warnings may be used...
A)to warn of the intention to overtake only within built-up areas.
B)on wide roads with few bends.
C)on narrow roads with many bends.Correct
Acoustic warnings may only be used exceptionally to avoid a possible accident, especially on narrow roads with many bends, to warn outside built-up areas of the intention to overtake, or to alert other road users of one's presence when carrying out an emergency service.