He was in a dejected mood.

Answer: Option C

Dejected : sad and depressed; dispirited.
Irritable : having or showing a tendency to be easily annoyed.
Romantic : conducive to or characterized by the expression of love.
Jubilant : feeling or expressing great happiness and triumph.
Rejected : dismiss as inadequate, unacceptable, or faulty.

Antonym of Dejected is Jubilant