The majority of Certinia PSA's operational and business logic settings are managed through two primary mechanisms. Configuration Groups are a core PSA feature that allows administrators to define and apply sets of rules and behaviors to different parts of the organization, such as regions, practices, or groups. This provides granular control over features like timecards, expenses, and project management. Custom Settings are a Salesforce platform feature heavily utilized by PSA to store application-wide or profile-level configurations that control global behavior, integrations, and foundational logic. The PSA Administration page acts as a central console but primarily links to these and other setup areas.

C. PSA Administration Page: This page is a central hub for administrative tasks and a starting point for configuration, but it is not where the majority of the detailed business logic settings are directly stored or managed.

1. Certinia PSA Administration Guide, "Configuration Options". This section details how Configuration Groups are used to control the behavior of PSA for different sets of users, covering settings for timecards, expenses, project management, and more. It establishes Configuration Groups as a primary area for settings.

2. Certinia PSA Administration Guide, "Custom Settings". This section lists and describes the numerous custom settings used by PSA to control application-wide behavior. It explicitly states that PSA uses custom settings to store a variety of configuration options, confirming it as a major settings area.

3. Certinia PSA Administration Guide, "Administration Tab". The documentation describes this tab as a central console providing access to various administrative functions, health checks, and links to other setup pages, rather than being the direct location for the bulk of configuration settings itself.