What is the meaning of the following traffic sign?

- Correct answer: It is obligatory to stop for customs inspection
- Slow down for passport control.
- It is obligatory to stop if you have somrthing to declare only.
- No need to stop for custom controls (This is a duty-free facility).
Why this is the answer
The correct answer in the official bank: It is obligatory to stop for customs inspection
This round red-bordered sign with a black bar and the word customs requires every driver to stop for customs inspection. The stop applies to all vehicles, even if the driver has nothing to declare. You may continue only after the officials allow it. It is not about passport control or a duty-free facility.