As a network engineer， you responsibility is to install， configure， operate， and troubleshoot networks. In your company’s network， EIGRP is the routing protocol. You have just discovered that two routers restarted the neighbor relationship.Why？ （）

• A、An update packet with init flag set from a known， already established neighbor relationship was received by one of the routers.
• B、The counters were deleted.
• C、The ARP cache was removed.
• D、The IP EIGRP neighbor relationship was cleared manually.