Courtesy does not cost one anything.

Answer: Option B

Gentility : social superiority as demonstrated by polite and respectable manners, behaviour, or appearances.
Civility : formal politeness and courtesy in behaviour or speech.
Amiability : the quality of having a friendly and pleasant manner; geniality.
Urbanity : courteousness and refinement of manner.
Courtesy : the showing of politeness in one's attitude and behaviour towards others.

Synonym of Courtesy is Civility