Correct option is B
Option (b) is the correct synonym of the given word.
Exciting means causing a sense of enthusiasm, interest, or exhilaration.
Synonyms: Thrilling, stimulating, exhilarating, electrifying.
Antonyms: Boring, dull, uninteresting.
Meanings of all options-
Dreary: Depressingly dull or bleak.
Electrifying: Thrilling and full of excitement.
Moral: Relating to principles of right and wrong behavior.
Vengeful: Desiring revenge or seeking to inflict harm in return for a wrong.