Which statement is true about configuring a back-to-back connection frame-relay on Juniper Routers?（）

• A、Both DTE and DCE will send keep-alives by default so no special configuration is required.
• B、The circuit is negotiated automatically so no special configuration is required.
• C、All equipment is by default DTE, one side should be set to DCE
• D、All equipment is by default DCE, one side should be set to DTE