Which of the following is the primary purpose of a service that tracks log-ins and time spent using the service?

Accounting, in the context of security, refers to the process of tracking user activities, including log-ins, log-outs, and resource consumption. This data is crucial for auditing, identifying suspicious behavior, and ensuring accountability. While availability ensures the service is accessible, authentication verifies user identity, and authorization grants specific permissions, none of these directly address the tracking of usage details like log-in times and duration of service use. Accounting is specifically designed for this monitoring and record-keeping function.