Implementing client certificate authentication requires configuration on both the gateway and the client, involving trusted CAS and certificate distribution. - Option A (Correct): The Gateway needs to trust the CA that issued the client certificates. Importing the Client CA (the root or intermediate CA that signed the client certificates) and configuring an Authentication Profile to use certificate authentication referencing this CA enables the gateway to validate client certificates. - Option B (Correct): Each endpoint that will authenticate using a certificate must have a unique client certificate installed and available. - Option C (Correct): The GlobalProtect Agent configuration on the endpoint must be set up to present the client certificate during the authentication process when connecting to the configured gateway. - Option D (Correct): While this option repeats a concept from the previous question, it's relevant here. The client needs to trust the gateway's server certificate for the tunnel to be established securely in the first place, regardless of whether the client is also presenting its own certificate. - Option E (Incorrect): SSL Inbound Inspection is for decrypting incoming traffic destined for internal servers, not for authenticating GlobalProtect clients to the gateway.