The correct answer is C. consideration.
A man who is well-bred and honourable invariably shows consideration for the feelings of other people. This means that he is mindful of how his actions and words might affect others, and he takes steps to avoid causing harm or offense. He is also willing to listen to and understand the perspectives of others, even if they differ from his own.
Complacency is a state of being satisfied with oneself or one’s situation, often to the point of being unaware of or unwilling to consider the need for improvement. This is not a characteristic of a well-bred and honourable man.
Concern is a feeling of worry or anxiety about something. This is a characteristic of a well-bred and honourable man, but it is not the only characteristic that he possesses.
Contempt is a feeling of deep disgust or disapproval. This is not a characteristic of a well-bred and honourable man.