I believe it would be a soliloquy. A soliloquy is defined as a person speaking to themselves without any regard for someone that may hear it (or oblivious to them).
The answer for your question is B: Formal
Answer:
Ohayo, Haruki-kun here!
Jem and Scout find gifts in the oak tree.
The children act out Boo Radley's life story.
Explanation:
Answer:
I think it's A.understatement and irony.
Explanation: