[单项选择] You have an existing Windows Communication Foundation (WCF) service that exposes a service contract over HTTP. You need to expose that contract over HTTP and TCP. What should you do?() A. Add a net.tcp base address to the host. B. Add an endpoint configured with a netTcpBinding. C. Add an endpoint behavior named netTcpBehavior to the existing endpoint. D. Add a binding configuration to the existing endpoint named netTcpBinding.