Concept:The idiom “too clever by half” describes someone who is overly proud of their own intelligence in a way that annoys other people.
Explanation:The phrase “by half” adds emphasis and means “too much” or “excessively”.
It does not mean that the person is actually less intelligent than they think.
It also does not mean that the person pleases everyone or hides their real cleverness.
Instead, it shows that the person’s display of cleverness is irritating to others.
Therefore, the correct interpretation is based on this sense of annoying overconfidence.
Answer:A. displays his cleverness in an annoying way