Your firm is procuring a third-party LLM to summarize client contracts containing privileged legal data. The vendor's standard agreement permits using customer inputs to improve their model. What should the security architect recommend FIRST?
A. Negotiate a contract addendum prohibiting input use for model training
B. Conduct a data flow and risk assessment to classify exposure boundaries
C. Require the vendor to deploy a tenant-isolated model instance
D. Implement DLP controls to redact privileged content before submission