From the words lettered A to D below each of the following sentences, choose the word that is nearest in meaning to the underlined word.
The dissidents held several clandestine meetings before the attack.
The Principal warned the final-year students about the consequences of procrastination.
The incessant chatter of the pupils irritated the teacher.
With his cogent argument in favour of the proposal, he was able to check further opposition.
The professor's explanation of that point was quite lucid.
