Which sentence uses correct subject-verb agreement in the subjunctive mood? a) he acts as if he was guilty. b) she wishes her boyfriend were here. c) we would have passed the test if we studied harder. d) if john was more aggressive, he is a better hockey player.

The correct answer is B. She wishes her boyfriend were here

Explanation:

In different languages including the English language the subjunctive mood refers to a set of grammatical structures that express situations that are not likely to become real, are completely unreal or have not occurred yet this includes desires, wishes, possibilities, purposes, among others. One of the grammatical structures used as part of the subjunctive mood is the conditionals which in case of unreal statements use the simple past to express unreal situations or the past perfect along with modal verbs such as would, might or should; additionally to this, the use of "were" for all the pronouns whether these are singular or plural show a subjunctive mood and therefore if the situation refers to something unreal "were" should be used instead of "was" for singular nouns, which is an exception to subject-verb agreement rules. Considering this, the sentence "She wishes her boyfriend were here" is the sentence that uses correctly the subject-verb agreement in the subjunctive mood as even when the noun "boyfriend" is singular the use of "were" for the subjunctive mood is correct for singular nouns.