The correct answer is: "Adding a custom certificate authority (CA) or custom CA bundle to your gateway's trust store for mTLS is optional unless you need to reject certificates that do not contain particular values (such as a domain name)." The statement that is NOT valid regarding the mTLS options in OCI API Gateway is: "Adding a custom certificate authority (CA) or custom CA bundle to your gateway's trust store for mTLS is optional unless you need to reject certificates that do not contain particular values (such as a domain name)." In OCI API Gateway, adding a custom certificate authority (CA) or custom CA bundle to the gateway's trust store is not optional. It is a necessary step when configuring mTLS authentication. The trust store in the gateway is used to validate the client certificates presented during mTLS authentication. The other options listed are valid regarding the mTLS options in OCI API Gateway: Once the mTLS request policy is enabled, all requests with valid certificates are routed to the backend unless specific values (such as a domain name) are defined. This means that only requests with valid client certificates will be allowed to access the backend microservices. The mTLS request policy can only be enabled at the API deployment specification level, and it applies globally to all routes in that deployment. This ensures consistent mTLS authentication across all routes and endpoints in the API deployment. Custom CA or custom CA bundles can be added to the gateway's trust store, but only if they already exist in the OCI Certificates service. This allows you to include trusted CAs or CA bundles to validate client certificates during mTLS authentication.