All family members of the Template part are _______.

The correct choice is that all family members of the Template part are read-only. In Siemens NX, template parts are designed to serve as master files that establish standards for design practices within a given project. When family members are derived from a template part, they inherit the parameters and features defined in the template, but they cannot be altered directly.

This read-only status ensures that the integrity of the template is maintained, providing a consistent foundation for related parts. While users can create instance variations based on the template, any modifications to the family members do not affect the original template. This characteristic is crucial in environments where standardization and consistency are prioritized, allowing designers to work efficiently without compromising on design integrity.

In contrast, being selectable, clones, or independent would imply variations that could lead to unintended changes or alterations within the template system, which contradicts the purpose of using a Template part in NX. By ensuring that family members remain read-only, the software reinforces its structured approach to design and part management.