What are two reasons that duplex mismatches can be difficult to diagnose? (Choose two.)

A.
The interface displays a connected (up/up) state even when the duplex settings are mismatched.

B.
The symptoms of a duplex mismatch may be intermittent.

C.
Autonegotiation is disabled.

D.
Full-duplex interfaces use CSMA/CD logic, so mismatches may be disguised by collisions.

E.
1-Gbps interfaces are full-duplex by default.