Which options can be used to source a read-only value?

The selection of property value, constant, and localize property value as the correct choice for sourcing a read-only value is grounded in the nature of these options and their usage within the Pega platform.

Property values are fundamental components in Pega applications and can be defined to hold static (read-only) information that does not change during the user interaction with the system, such as a customer's status or an identifier that is not expected to modify.

Constants are fixed values defined in the application and are inherently read-only. They are typically used to represent values that should not change, such as the maximum allowed transactions or specific thresholds.

Localized property values are useful for applications that operate across different languages and regions. These values can be set to display messages or information in a way that is specific to the user's locale. Since these values don't change dynamically and are meant to deliver consistent information according to localization settings, they also serve the purpose of read-only fields.

In contrast, options like external database and web service, while they can provide data, typically involve interactions that may allow changes or updates, making them unsuitable for strictly read-only values within certain contexts. Similarly, generated values can change based on certain triggers, and temporary storage is usually volatile, which doesn’t fit