Option B is correct because output filtering examines the chatbot’s generated response before it reaches the requester and blocks or redacts sensitive information such as a patient’s phone number. In this scenario, the requester uses urgency and a claimed family relationship to pressure the model, but the chatbot must not disclose protected personal data without verified authorization. An output filter can detect personally identifiable or health-related information, apply policy rules, replace the value with a refusal, and log the event for review. Option A standardizes prompts but cannot guarantee that the model will not produce sensitive content. Option C encrypts the communication channel, protecting data from interception in transit, but it would still deliver the prohibited information securely to an unauthorized person. Option D masks data before model use and can reduce exposure, but the question asks for a compensating control that prevents disclosure in the chatbot response; runtime output filtering is the most direct choice. The NIST AI Risk Management Framework links trustworthy AI with privacy enhancement and protection of confidentiality, supporting controls that prevent inappropriate disclosure.