If the options are metaphor, alliteration, allusion, and apostrophe, I believe the answer is metaphor, because the others don't fit.
Alliteration is the repetition of a consonant.
Allusion is reference to something or somebody outside of that literary work.
And apostrophe is the author speaking directly to somebody outside the poem, usually gods or a muse.
It’s an adjective because it’s describing it
Answer:
it was shaped like "an" egg.
Explanation:
you would finish the sentence with "an" because all if theres a vowel you say "an." if its not a vowel you say "a". but in this case its "an." hope this helpss! :))