Which circumstance allows a lawyer to reveal client information without authorization?

The correct answer highlights a crucial aspect of professional responsibility concerning lawyer-client confidentiality. Attorneys may disclose client information without authorization in order to secure legal advice regarding their own compliance with professional conduct rules. This exception recognizes the necessity for lawyers to seek guidance on how to fulfill their ethical obligations while navigating complicated situations.

In this context, if a lawyer believes they might be engaging in conduct that could violate the rules of professional responsibility, disclosing client information to obtain legal advice helps ensure they handle the matter ethically and within the bounds of the law. It maintains an important balance between upholding client confidentiality and allowing lawyers to operate within legal and ethical frameworks.

The other options do not provide appropriate grounds for disclosure. For instance, revealing information to prevent future crimes could imply a more significant ethical dilemma, while using client information to gain an advantage in litigation would typically violate the duty to maintain client confidentiality. Notifying authorities of past crimes also raises complex issues which generally do not override the confidentiality owed to clients, unless certain conditions apply (like preventing serious harm).