There are three types of firewalls;-
- Layer 3 Firewall or Packet Filtering Firewall
- Layer 4 Firewall
- Layer 5 firewall or Proxy Firewall
As the name suggests, Packet filtering firewall can operate only upto Network Layer.
Options A and B deals with events at Application Layer.
Option C deals with Transport Layer
Option D deals with IP addresses at Network Layer, which comes under the operational capabilities of Packet Filtering Firewall.