Choose the appropriate articles for the given sentence:
They were having _______ essential debate on the topic of child labour in ______ auditorium.

Correct option is D

The correct articles for the given sentence are an and the.
Reason for the correct answer:
The word "essential" starts with a vowel sound, so "an" is the appropriate article. "The auditorium" is used when referring to a specific auditorium that both the speaker and listener are aware of.
Grammatical rule involved:
· Use "an" before words that begin with a vowel sound, regardless of the actual first letter.
· Use "the" when referring to something specific or already known to the listener.
Meanings of the other given options:
· The, a: Incorrect because "the essential debate" implies a specific debate already known, which isn’t indicated here.
· A, the: Incorrect because "a essential" is grammatically incorrect; it should be "an essential."
· A, a: Incorrect for the same reason as above; "a essential" is wrong, and "a auditorium" is also wrong since "auditorium" starts with a vowel sound.