It is "over the mantelpiece." This is because "over" is a preposition that is telling you where the painting is hanging.
- - C.<span>He; subject
This is because if "X and Harold" are the subjects, and to complete this using "he", it would also have to be a subject.
He and Harold </span><span>are going on a camping trip next month.</span>
Answer:
Explain what the message of the story is. :)