How is courtesy best described?

Courtesy is best described as polite behavior, gesture, or remark. It embodies an attitude of respect and consideration for others, which is essential in building positive interactions and relationships. Courtesy involves actions such as saying "please" and "thank you," being attentive to the needs of others, and showing kindness in both words and actions. These behaviors help foster a sense of mutual respect and understanding, which are crucial in any social or professional setting.

The other options reflect attitudes and behaviors that do not align with the definition of courtesy. Indifferent behavior towards others shows a lack of concern or consideration, while acting solely for personal gain demonstrates selfishness rather than the respect for others that courtesy embodies. Rude dismissal of opinions is clearly the antithesis of courteous behavior, as it disregards the feelings and perspectives of others.