You are working as a network technician， study the exhibit carefully. Your boss has informed youthat there have been problems with the WAN that is using EIGRP routing protocol. You arerequired to troubleshoot these problems. Before going to the questions of this sim， we should have a quick review about GRE tunneling：GRE Quick Summary. The picture below shows how to configure a GRE Tunnel between two routers， notice that the"tunnel destination" must be the IP address of the interface， not of the opposite tunnel. Notice： The tunnel source on one router must be specified as the tunnel destination on the otherrouter. Below are the questions of this lab-sim. What is preventing the HQ router and the Branch1 router from building up an EIGRP neighborrelationship？（）

• A、When running EIGRP over GRE tunnels， you must manually configure the neighbor addressusing the eigrp neighbor ipaddress command
• B、The tunnel destination address is incorrect on the HQ router. It should be 10.2.1.1 to match theinterface address of the Branch1 router
• C、The tunnel source is incorrect on the Branch1 router. It should be serial 2/0
• D、The default route is missing from the Branch1 router
• E、The tunnel interface numbers for the tunnel between the HQ router and Branch1 router do notmatch