All the batsmen . . . . . . . . had scored half century in the semi final of IPL were invited to a tea party by the Prime Minister of India. A. who B. whom C. that D. which

The correct answer is: A. who

The other options are incorrect because they are not relative pronouns.

• Whom is a relative pronoun that is used to refer to the object of a verb or preposition. In this sentence, the batsmen are the subjects of the verb “had scored,” so we cannot use “whom.”
• That is a relative pronoun that can be used to refer to both subjects and objects. However, in this sentence, it would be ambiguous to use “that” because it could refer to either the batsmen or the half centuries.
• Which is a relative pronoun that is used to refer to non-essential information. In this sentence, the information about the batsmen scoring half centuries is essential to the meaning of the sentence, so we cannot use “which.”

Here is a rewritten version of the sentence that uses the correct relative pronoun:

The Prime Minister of India invited all the batsmen who had scored half centuries in the semi final of IPL to a tea party.