Hughie is characterized as:
C. As wealthy and successful, yet not very bright.
Explanation:
In the story 'The Model Millionaire' Wilde characterizes them straightaway as if to condense their personality into quips and make a question of lack of personality in the face of materialistic possessions and their discussion that seems to be the case here..
Hughie is the protagonist of the story and thus is the center of this discussion.
He is shown to be a good person by nature and that he is wealthy and successful but he is shown not as a bright person particularly.
it is clear that his wealth is not there because of his wits.