Answer:
the choice and use of words and phrases in speech or writing.
Explanation:
I believe the last one. A dangling modifier is a word or phrase that defines something or someone not spoken about in the sentence. So "a successful career as an author seemed certain", but seemed certain to who? A fair warning: I could be wrong.
In Frank Stockton's short story "The Lady or the Tiger", I think the author's purpose is to present a familiar fairy tale with an ending which will provoke enthusiastic discussion about which choice the princess made. We all make decisions and with decisions come consequences.