‘Murmur’ is a low continuous background noise that is generally used to describe the way someone speaks, i.e. a softly spoken or almost inaudible utterance. Similarly ‘mutter’ and ‘mumble’ mean to say something in a low or inaudible voice. All the three words are commonly associated with the way people speak. Therefore ‘murmur’, ‘mutter’ and ‘mumble’ cannot be associated with a clock; hence options A, B and D are incorrect. On the other hand, ‘chime’ means a melodious ringing sound that is produced when a bell or metal bar is struck. Since the clock has a metal bar that chimes at the stroke of each hour ‘chime’ is the apt answer. Therefore option C is correct.