Correct Answer :
A. The student, who the friends have nicknamed
The student, whom the ……
The relative pronoun whom is used with the Accusative and the relative pronoun who with the Nominative.
When a pronoun or, noun) is used as the Subject al a verb if a raid to be in the Nominative case and when it is used as the Object of a verb it is said to be in the Accusative Case.
To find the Nominative, put Who/What before the verb and to find the Accusative put Whom/What before the verb and its subject.
WhomWhat have the friends (subject) nicknamed as Jolly John (object)?
It is the relative pronoun who which has different forms for Accusative (i.e. whom) and Genitive (i.e. whose).
The case of a relative pronoun depends upon the use oi the pronoun in the clause which it Genitive (i.e. whose) introduces not upon the case of its antecedent.
Compare the following two sentences in which the antecedent (i.e. the noun to which the pronoun refers or relates) is in the Nominative case but the pronouns are in the nominative and accusative cases, respectively, because of their use in their own clauses.
This he who came yesterday. (nominativesubject of the verb came)
This is he whom you saw. (accusative object of saw)
The student who is selected must be reliable. (subject of the verb is selected)
The student whom you select must be reliable. (object of the verb select) Whom do you want? (object of the verb do want)Who do you think will be there? (subject of the verb will be)