which Linux based firewall tool?

ESX uses which Linux based firewall tool?

A.
IPCop

B.
IPTables

C.
monowall

D.
FireStarter

Explanation:
Mastering VMware vSphere 4, page 564

VMware ESX ships with a firewall that controls traffic into and out of the Service Console. This firewall is based on the Linux iptables firewall.