The two most common ways to expose your application to an external system are to leverage the Pega API (B) and to create a web service with the Service wizard (D). The Pega API provides a set of out-of-the-box RESTful endpoints for performing operations within the Pega Platform. The Service wizard simplifies the creation of SOAP or REST services, enabling external systems to interact with Pega applications.Reference: Pega Community documentation on Pega API and Service wizard.

To include access groups in your Product rule, you can:
* A: Associate the access groups with a ruleset included in the application. This ensures that when the ruleset is included in the product rule, the associated access groups are also included.
* D: Add the access group directly to the Product record in the Individual instances to include section.
This allows you to specifically select which access groups to include in the product rule. References:
Pega official documentation on Product rules.

A native app is suitable for remote areas without internet access because it can be installed on the device and has the capability to function offline. This allows the courier company employees to scan and track parcels regardless of internet connectivity. Reference: Pega Mobile Client Developer Guide.

Controlling access to an attachment category can be achieved through various configurations. Using a When condition like "IsCurrentStageTesting" (A) allows for dynamic access control based on the case's current stage, enabling attachments to be accessible only under certain conditions. Assigning privileges, such as "DeleteOwn" (C), to users enables fine-grained control over actions users can perform on attachments, such as deleting their own attachments, thus enhancing security and compliance with business rules.Reference: Pega Community documentation on attachment categories and access control.