Lightheartedness means cheerful, carefree ect.
This means the line "The sounds of water splashing and laughter echoed in the distance; Tim's friend's had gone for a late-night swim." is the phrase that is the correct answer, since it talks about the happy actions of Tim's friends.
Answer C.
C, it’s the only one that relates to the claim.
The correct answer is B. Byron himself
Byron presented his early life in the story of Childe Harold in which he regretted his wasted youth and wished he could change things.
The mouse ran up the clock.
Takes ownership of another country. hope this helps:)