there is an explanation given by an expert here.

the OA is D.

But I request experts to help me to understand this in the light of command subjunctive, which uses a plural verb, but the "bring" here doesn't seems to be a plural verb.

The subjunctive verbs follow a particular structure which is:
Demand/Request/Recommend Word + THAT + Subject + Subjunctive Verb .

richachampion wrote:there is an explanation given by an expert here.

the OA is D.

But I request experts to help me to understand this in the light of command subjunctive, which uses a plural verb, but the "bring" here doesn't seems to be a plural verb.

The subjunctive verbs follow a particular structure which is:
Demand/Request/Recommend Word + THAT + Subject + Subjunctive Verb .

The key is to internalize that the subjunctive verb, in the construction you outlined above, takes the form of a naked infinitive. This is true irrespective of whether the preceding subject is singular or plural. (The infinitive is the "to" form of the verb. If "to bring" is the infinitive, then "bring" is the naked infinitive. If "to be" is the infinitive, then "be" is the naked infinitive. And so forth.)

This is the distinction -
A simple sentence with indicative mood: Dave brings a cake to every party he attends.
A sentence in the subjunctive mood: The caterer insisted that Dave bring a cake to the party.