What are two possible causes for EIGRP Stuck-In-Active routes?

While troubleshooting an EIGRP routing problem you notice that one of the routers have
generated a large number of SIA messages. What are two possible causes for EIGRP
Stuck-In-Active routes? (Select two)

A.
Some query or reply packets are lost between the routers.

B.
The neighboring router starts receiving route updates from this router.

C.
A failure causes traffic on a link between two neighboring routers to flow in only one
direction (unidirectional link).

D.
The neighboring router stops receiving ACK packets from this router.