What configuration allows users to enter time only on task lines in PSA?

The correct choice revolves around the configuration that allows specifically for time entry on task lines within the Professional Services Automation (PSA) system. Custom settings and fields are pivotal in tailoring the user experience and enforcing specific data entry requirements.

In this scenario, allowing users to input time exclusively on task lines is a function of customizing how tasks and timecards are integrated in the system. By leveraging custom settings, administrators can configure the system to dictate where and how users can enter time, ensuring that entries are correctly aligned with tasks.

Custom settings enable organizations to refine the user interface and capabilities according to their operational needs, thus simplifying processes and ensuring that users adhere to specific protocols—like entering time only on task lines. This configuration supports the workflow, promotes accuracy, and minimizes confusion among users.

Other configurations, such as role settings, standard page settings, or project management options, may not specifically control the granularity of where time can be entered, making custom settings essential in this context.