The correct answer is:
C. The person loves chocolate.
Explanation:
In British English, the phrase "doesn't half" is often used informally to mean "really" or "very much." It emphasizes the statement, so the sentence:
"My brother doesn't half love chocolate"
actually means "My brother really loves chocolate."
This usage might be confusing because of the negative-sounding structure, but it’s positive in meaning when used this way.