Genteel

Genteel means a person who is characterized by high class and refinement.Polite means behaving in a way respectful of other people.So, both polite and genteel means to behave in a well-mannered way with others.Therefore, option B is the right answer.Lovable means having a character that easily attracts affection and does not necessarily imply to behave in a manner considerate of others.Thus, option D is wrong.Hopeful and clever doesn't have any similarity to the meaning of genteel.