Which of the following is not considered unethical behavior?

Courtesy is the correct choice because it embodies behaviors that are respectful, considerate, and professional in nature. In the context of public safety telecommunications, courtesy is essential for establishing a positive rapport with callers and other emergency personnel, ensuring effective communication and fostering trust during critical incidents.

In contrast, prejudice, willful neglect of duty, and sexual harassment all represent unethical behaviors that harm individuals or undermine the integrity of the workplace. Prejudice can lead to discriminatory practices, neglecting one's duties can endanger public safety, and sexual harassment creates a toxic environment. Thus, courtesy stands out as a fundamental component of ethical conduct, making it the only option that is not considered unethical behavior.