When is it required to brake only one wheel in a tractor (brake separation)?

1. A When the tractor driver wants to make a maneuver in a particularly large radius between structures or crops.
2. B When one wheel slides against the ground and the tractor cannot proceed.
3. C When the tractor driver wants to make a sharp turn on the spot while driving at a high speed.
4. D When the tractor driver wants to make a sharp turn on the spot while driving at a very slow speed.