Right answer is D: A proxy service listener specifies where a ProxySG service listens for traffic. Four attributes comprise the listener: • Source IP address—Typically “All”, which means any IP address that originates the request. • Destination IP address—Transparent acts on connections without awareness from the client or server. Explicit sends requests explicitly to a proxy instead of to the OCS. • Port—A specific port or port range. All default ProxySG services are configured to their industry-standard ports; for example, the Explicit HTTP service is configured to listen on ports 80 and 8080.