Which pieces of information does a basic packet filter use to make its decision? Choose three.

Answer: C. The interface the packet crossed and its direction.
B. Source and destination IP address.
D. The network or transport protocol in use, and transport ports where the protocol has them.

A packet filter works from source and destination address, the protocol, transport session ports where present, and the interface traversed with its direction. Application content is beyond it.

Source: NIST SP 800-41 Rev. 1 (NIST) — SP 800-41 Rev. 1 > 2.1.1 Packet Filtering