A lien against a registered person is a reportable financial event that must be disclosed on the individual’s registration record. The mechanism for updating that record is an amended Form U4, and firms are required to update Form U4 disclosures promptly (commonly tested as within 30 days after the firm learns of the event). Therefore, the correct answer is A. Form U4 is the Uniform Application for Securities Industry Registration or Transfer and is used not only for initial registration but also for ongoing updates to disclosure items, including certain financial matters such as liens, judgments, and bankruptcies when required.

Choice B is incorrect because Form BD is the broker-dealer’s registration form (the firm’s registration), used for firm-level changes and disclosures. A lien filed against an individual RR is not handled by updating the broker-dealer’s Form BD. Choice C is incorrect because fingerprinting requirements relate to identity/background checks and are not the reporting mechanism for financial liens. Choice D is incorrect because FINRA Rule 4530 generally concerns reporting of certain events such as regulatory actions, violations, and specified misconduct; a personal lien is addressed through the representative’s disclosure updates rather than being a “customer complaint report” filing. (Also, the question’s “complaint report” phrasing is a distractor—liens are not customer complaints.)

On the SIE, the point is recognizing where disclosures live (Form U4 for associated persons) and the expectation that firms supervise and update registration records when reportable events occur.