The correct option is B elated
The term "dejected" means being sad and depressed. Elated means being ecstatically happy. Sadness and happiness are opposite traits. Hence, Option A is correct. Among the rest of the options, impressed means feeling or showing admiration or respect for someone or something, hilarious means extremely amusing, relieved means no longer feeling distressed or anxious; reassured. These options do not express this antonym, hence incorrect.