The correct answer is A, Form U4. Form U4 (Uniform Application for Securities Industry Registration or Transfer) must be kept current at all times and updated promptly—generally within 30 days—whenever a registered representative experiences a reportable event, including criminal matters such as a guilty plea.

Step-by-step, a guilty plea to an investment fraud scheme is considered a material disclosure event, even if the misconduct occurred years earlier. The key factor is the date of the guilty plea, not when the underlying activity occurred. This triggers the obligation to update Form U4 so regulators (such as FINRA and the SEC) have accurate and current information about the individual’s disciplinary history.

Choice B, Form U5, is used when a registered representative leaves a firm and is not relevant to ongoing disclosures. Choice C, arbitration disclosure, pertains to dispute resolution records, not regulatory filings. Choice D, written supervisory procedures (WSPs), are internal firm compliance documents and do not relate to individual disclosure updates.

Thus, any criminal event such as a guilty plea must be reported through an updated Form U4 within 30 days, making Answer A correct.