This is a common English Language (Grammar) question from competitive government exams. Below is the answer plus the fastest trick to solve it under exam time pressure.

Question

Choose the grammatically correct sentence: (a) It is essential that he attends the meeting. (b) It is essential that he attend the meeting. (c) It is essential that he attending the meeting. (d) It is essential that he will attend the meeting.

Answer & Explanation

Look at the pattern “It is + adjective + that …”.
When the clause after that expresses a necessity, importance, demand, suggestion, etc., English uses the subjunctive – the verb appears in its base form (no –s, no –ed, no –ing, no “will”).

So scan each option:

a) “…that he attends the meeting.” – verb has –s → ordinary indicative, not the subjunctive. Wrong.
b) “…that he attend the meeting.” – base form, fits the subjunctive after “essential”. Correct.
c) “…that he attending the meeting.” – gerund form, not allowed after “essential that”. Wrong.
d) “…that he will attend the meeting.” – future auxiliary “will” is not used in the subjunctive construction. Wrong.

Quick rule: After “It is essential/important/necessary/imperative that …”, drop the –s (or any tense marker) and use the bare verb. The only choice that follows this rule is (b) It is essential that he attend the meeting.