Final answer:
The sentence 'The new member of the discussion panel may be he.' requires a pronoun in the nominative or subjective case, making Option A: nominative the correct answer.
Step-by-step explanation:
The correct answer to the question "The new member of the discussion panel may be he." is Option A: nominative. This is because the pronoun 'he' is subject to the verb 'may be' and therefore should be in the subjective case, which functions as the subject of the clause or sentence. Remember, subjective case pronouns function as subjects, for example, 'Antonio and I share an apartment downtown'. Other forms of pronouns, such as the objective case like 'me', and possessive case pronouns like 'mine', are used differently within sentences.
Using the correct pronoun case is vital in English grammar, and the subjective case is used when the pronoun is doing the action of the sentence. In contrast, pronouns like 'him' or 'her' would be used in the objective case when the pronoun is receiving the action of the verb, and possessive pronouns like 'his' or 'hers' show ownership or relation.