Directions: Choose the most appropriate word from the given options and fill the gap.

He was playing the music system, but I told him to _____ because neighbors were complaining about the noise.

The correct answer is 'leave off' (option B). The phrasal verb 'leave off' means to stop doing something, especially something annoying. In this context, the neighbor is complaining about noise from the music system, so 'leave off' is the appropriate choice meaning 'stop playing'. 'Leave down', 'leave away', and 'leave for' are not standard phrasal verbs with relevant meanings in this context.