From the words lettered A to D, choose the word or group of words that best completes the sentence. The pupils were advised not to laugh....mad people.

From the words lettered A to D, choose the word or group of words that best completes the sentence.
The pupils were advised not to laugh....mad people.

Answer Details

The correct answer is "at". The preposition "at" is used to show the object or person that is being laughed at. In this case, the object is "mad people". So the sentence should be "The pupils were advised not to laugh at mad people."