In computing, ________ is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules.

The correct answer is option 4) i.e. Firewall.

• A firewall is a type of computer-security system.
• A firewall controls the flow of data from one computer or network to another and they are mainly intended to protect an individual computer system or a network from being accessed by an intruder, especially via the Internet.

Note:

• Cookies are small files that are stored on a user's computer. They are designed to hold a modest amount of data specific to a particular client and website and can be accessed either by the web server or the client computer. 
• Spam is an undesired or illegal email message.
• Spyware is unwanted software that infiltrates your computing device, stealing your internet usage data and sensitive information.