Explanation:

- Exultation is a feeling or expression of extreme joy or triumph. It's a moment of great happiness and celebration.

- Depression refers to a state of severe despondency and dejection, often linked to sadness or hopelessness. It is the opposite of exultation.

- Agitation is a state of anxiety or nervous excitement. It doesn’t match the meaning related to joy or celebration.

- Irritation is a feeling of being annoyed or provoked. It’s nowhere near the joy expressed in exultation.

- Jubilation is a feeling of great happiness and triumph, very similar to exultation. It involves a high level of joy typically shared in a celebration.

- Jubilation is indeed the most appropriate synonym for exultation.