Which permission set would be more appropriate for an advanced user who needs to perform substantial tasks within the system?

The choice of Power User as the most appropriate permission set for an advanced user stems from the additional capabilities and functionalities it offers compared to other options. A Power User is designed for individuals who require a deeper level of access and who frequently interact with various aspects of the system. This permission set allows the user to perform significant tasks, such as creating and adjusting plans, generating reports, and managing data at a more intricate level.

This role typically includes permissions that let users not only view data but also make substantial changes and perform advanced operations, which aligns with the needs of someone who is considered an advanced user. Such users are often responsible for analyzing data, collaborating on planning processes, and ensuring that systems operate efficiently.

In contrast, options like Contributor might provide some level of interaction, but they typically have more limited capabilities compared to Power Users. The View Only option is too restrictive as it only allows for data observation without the ability to make modifications. The Defining New Permission Set would be suitable for administrative purposes and doesn't align with the need for a user to perform substantial tasks in the system, as it involves configuring permissions rather than utilizing them for operational tasks.