Correct option is D
Explanation:
The tense "is going to leave" utilizes the present continuous to indicate a planned future action.
Information Booster:
Present continuous often expresses near-future plans, intentions, or scheduled events in English grammar. The auxiliary "is" and verb "going" in the 'ing' form confirm the tense.
Additional Knowledge:
(1) Present Indefinite uses "leaves" or "leave."
(2) Future Indefinite uses "will leave."
(3) Future Continuous uses "will be leaving."