Answer:
Charles' novel
Explanation:
In "The novel by Charles", the possessive noun should be 'Charles' because Charles wrote the novel, therefore it belongs to him.
When indicating possession, add apostrophe and the letter "s" at the end of the possessive noun : 's
You would think it looks like this: Charles's novel
However, there is another rule. When a word ends with the letter "s", you only put the apostrophe and do not need the second s.
Charles' novel
