You have been working as the network administrator for JP Steels. In order to cut down on operating costs, you plan to install a firewall's OS $($operating system$)$ in a VM on an inexpensive server, instead of purchasing an expensive hardware firewall to protect a LAN. Hence, you no longer require a firewall that runs on its own OS$.$ Which of the following firewalls will you purchase in this scenario?

a$.$ A firewall device by Palo Alto Networks

b$.$ A Cisco firewall device

c$.$ A Fortinet firewall device

d$.$ Barracuda's Cloudgen firewall device