Select the most appropriate option to substitute the underlined segment in the given sentence. If there is no need to substitute it, select ‘No replacement required’.

It is imperative that every applicant submits their paperwork before the closing date.

The correct answer is submit their paperwork before the closing date.

Explanation:
1. Subjunctive Mood: Sentences beginning with expressions of urgency, necessity, or command—such as "It is imperative that...", "It is essential that...", or "It is recommended that..."—require the use of the subjunctive mood in the dependent clause.
2. Base Verb Usage: In the subjunctive mood, the verb must always remain in its base (root) form, regardless of whether the subject is singular or plural. Therefore, the base form submit must be used instead of the third-person singular form submits.
3. Replacing the underlined segment yields the grammatically correct sentence: "It is imperative that every applicant submit their paperwork before the closing date."