Complete the following sentence using a suitable interrogative pronoun-
____ did you invite to preside over the meeting?
a. Whom
b. Who
c. What
d. Whose

Hint: Pronouns are words that are used in place of nouns to avoid repetition. ‘Interrogative pronouns’ are words that are used to ask questions or interrogate about something unknown. Example- What, whom, who etc.

Complete Answer: As given in the hint, there are mainly five interrogative pronouns- What, which, who, whom and whose.
Let’s look at the uses of the different interrogative pronouns-
What- It is used to ask questions about people, animals or things. Example- What is the name of that book?
Who- It is used as the subject of a verb to ask questions about people. Example- Who is that girl?
Whom- It is used as the object of the verb or the preposition to ask questions about people. Example- Whom did you see last night?
Whose- It is used to ask questions about possession cases. Example- Whose book is this?
In the given question: X is asking the subject, ‘Y’ whom he had invited to preside over the meeting.
Now, let’ examine the given options-
Option a- ‘Whom’ is used as the object of the verb. In the given interrogative sentence, we have used ‘whom’ as the object of the verb ‘invite’. Hence, it is the correct option.
Option b- ‘Who’ is used as the subject of the verb. Hence, it is an incorrect option.
Option c- ‘What’ is used in the nominative case. Hence, it is an incorrect option.
Option d- ‘Whose’ is used in the possessive case. Hence, it is an incorrect option.
The correct answer is Option ‘a’.

Note: We use the pronoun ‘whom’ as the object of the verb which is considered to be the correct form of the pronoun, but many native people tend to use ‘who’ as the object of the verb. Example- (1) Whom did you meet? (2) Who did you meet?