Final answer:
A namespace can indeed be unnamed and automatically scoped in, typically used to prevent name collisions and encapsulate contents within a single file in programming languages like C++. The correct option is T.
Step-by-step explanation:
True, a namespace can be unnamed and automatically scoped in. In the context of programming, particularly C++, an unnamed namespace, or anonymous namespace, is used within a .cpp file to indicate that its contents are intended to be local to that file only. By declaring a namespace without a name, you create a unique namespace which cannot be accessed by other translation units, thus preventing name collisions. The contents are automatically scoped in, meaning they are accessible without explicit namespace qualification within the translation unit they are declared in.
The correct option is T.