In the passage, what does the metaphor of a bird soaring in ecstasy signify?

a portrait of the artist as a young man

by james joyce (excerpt)

his heart trembled; his breath came faster and a wild spirit passed over his limbs as though he was soaring sunward. his heart trembled in an ecstasy of fear and his soul was in flight. his soul was soaring in an air beyond the world and the body he knew was purified in a breath and delivered of incertitude and made radiant and commingled with the element of the spirit. an ecstasy of flight made radiant his eyes and wild his breath and tremulous and wild and radiant his windswept limbs.

— one! two! look out!
— oh, cripes, i’m drownded!
— one! two! three and away!
— the next! the next!
— one! uk!
— stephaneforos!

his throat ached with a desire to cry aloud, the cry of a hawk or eagle on high, to cry piercingly of his deliverance to the winds. this was the call of life to his soul not the dull gross voice of the world of duties and despair, not the inhuman voice that had called him to the pale service of the altar. an instant of wild flight had delivered him and the cry of triumph which his lips withheld cleft his brain.

a) stephen's joy at having a sudden realization
b) stephen's gladness at being alone
c) stephen's hatred for social mores and rules
d) stephen's daydreaming about a pleasant life
e) stephen's excitement about his religious studies