Which of the following defines a countermeasure?

A countermeasure is defined as anything that lessens or mitigates a vulnerability, making option C the correct answer. In the context of information security, countermeasures are essential components of a risk management strategy. They are implemented to protect an organization's assets by reducing the risk associated with security threats and vulnerabilities.

Countermeasures can take various forms, such as technical controls, administrative policies, or physical barriers. For instance, installing firewalls, conducting employee training, or enforcing access controls are all examples of countermeasures aimed at protecting sensitive data and reducing the chance of security breaches.

While enhancing employee productivity, increasing technological efficiency, or documenting security processes are important aspects of organizational operations, they don’t directly address the concept of mitigating vulnerabilities specific to information security. Therefore, these options do not align with the definition of a countermeasure in the context of risk management and security frameworks.