Question: What is the expected behavior of a (U)SIM application's `main` function according to the C-language binding to (U)SIM API specifications?
Option 1: The application should return from `main` once all operations are completed.
Option 2: The application must call the `CatExit` function before returning from `main`.
Option 3: The `main` function can either return normally or call `CatExit`, depending on the application's design.
Option 4: The application should enter an infinite loop at the end of `main` to keep it running.
Explanation: According to the specifications, the application is not supposed to return from the `main` function. Instead, it must explicitly call the `CatExit` function when it needs to exit, ensuring a controlled shutdown or transition for proper resource management and potential notification of other components.