Final answer:
An attorney must D. report any unethical conduct that raises substantial questions about a lawyer's or judge's professional fitness to the appropriate disciplinary authority, according to professional ethical guidelines.
Step-by-step explanation:
When an attorney learns that another lawyer or a judge has engaged in unethical conduct that raises a substantial question.
As to the other lawyer's or judge's honesty, trustworthiness, or professional fitness, the attorney must report the conduct to the appropriate disciplinary authority. Option D is the correct answer.
It's important that all legal professionals adhere to ethical standards to maintain the integrity of the legal system.
Reporting to a legal association, ignoring the conduct, or notifying the media are not appropriate responses in this situation according to professional ethical guidelines for attorneys.