Her debonair manners were noticed by everyone present in the city.

Answer: Option B

Debonair : (of a man) confident, stylish, and charming.
Stiff : not easily bent or changed in shape; rigid.
Cheerless : gloomy; depressing.
Courteous : polite, respectful, or considerate in manner.
Pleasant : giving a sense of happy satisfaction or enjoyment.

Antonym of Debonair is Cheerless