Olivia wants to deploy a new firewall. What type of firewall should she select if the ability to operate at layer 7 is important to her?

Next-generation firewalls (NGFWs) typically provide the ability to inspect traffic at both the transport layer (layer 4) and the application layer (layer 7). This means an NGFW will best fit the need. Web application firewalls also work at this level, but only focus on web applications, which does not fully meet the broad application inspection requirement in the question. Stateful firewalls and packet filters both operate at layer 4 only.