Match the description to the type of firewall filtering. (Not all options are used.)

Stateful packet inspection: Prevents or allows access based on whether the traffic is in response to requests from internal hosts.
URL filtering: Prevents or allows access based on web addresses or keywords.
Application filtering: Prevents or allows access based on the port numbers used in the request.
Packet filtering: Prevents or allows access based on the IP or MAC addresses of the source and destination.