Answer:
to provide additional details about a main character's personality
Step-by-step explanation:
to prepare readers for sequels to the original text – this is not the right answer. The Hobbit does not have clear sequels, and if we consider the Lord of the Rings series as sequels, they don’t have anything to do with Belladonna.
to provide additional details about a main character's personality – this is the correct answer. Through explaining the character of his mother and her subplot, their relationship, and connections, Tolkien wanted to give readers more information about Bilbo himself, about his family and background, and with that, explain to us his character.
to directly address the readers of the text – this is not the right answer. Tolkien does not do this in this passage.
to develop a secondary character and storyline – this is not the correct answer. Tolkien does not use Belladonna further in the story much, so her development is not the right answer.