EIGRP is being used as the routing protocol on the PassGuide network. Whiletroubleshooting some network connectivity issues，you notice a large number of EIGRP SIA（StuckinActive）messages. What causes these SIA routes（）

A. The neighboring router stops receiving ACK packets from this router.
B. The neighboring router starts receiving route updates from this router.
C. The neighboring router is too busy to answer the query(generally caused by high CPU utilization).
D. The neighboring router is having memory problems and cannot allocate the memory to process the query or build the reply packet.