What is the mandatory driver action when facing a steady yellow (amber) traffic light under Article 89 of the Implementing Regulation?

1. Accelerate briskly to beat the red light before the phase changes
2. Stop before the stop line, unless the vehicle is so close that stopping cannot be done safely without causing a rear-end collision
3. Treat it as a green light and maintain speed through the intersection
4. Come to an immediate emergency skid stop regardless of trailing traffic