Which of the following software in a PC has inbuilt Firewall

Most routers have firewalls built-in, so if you're using a router (which most people do), you already have a good amount of protection from outside shenanigans. You also have a firewall on your computer, usually built in to Windows or Mac OS X. This one isn't as important to keep on, and there are some situations where you might need to turn it off: perhaps you've installed antivirus software that has its own firewall, or maybe you're running a program that isn't working correctly because it's conflicting with the firewall. But routers are situated outside PC and software in a PC having inbuilt Firewall are asked, only 1 & 4 will be the answer.