Which of the following is an example of a logical security control?

A logical security control specifically refers to mechanisms and techniques used to protect digital assets and information systems through software and processes rather than physical means. Firewalls serve as a prime example of logical security controls as they monitor and control incoming and outgoing network traffic based on predetermined security rules. By filtering traffic, firewalls protect computers and networks from unauthorized access and potential threats, which is crucial for maintaining the integrity and confidentiality of data.

In contrast, the other options focus on physical security measures. Locked doors and surveillance cameras are examples of physical controls that protect the physical premises where data and information systems reside. Security guards also fall under physical security measures, as they provide a human presence to deter and respond to security incidents on-site. While all these methods contribute to an overall security strategy, only firewalls represent a logical approach by specifically managing access at the network level.