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.
Without proper hygiene dogs can become matted and sick,just the same as any other human.
Answer:
Purchases of government bonds from banks