If the yellow ABS malfunction lamp stays on after the bulb check or comes on while driving, what should the driver remember?

1. The bus still has normal brakes, but the ABS may be lost and should be serviced soon
2. The bus has no brakes at all and must be abandoned immediately
3. The ABS lamp means the parking brake is set correctly
4. The driver should pump the brakes on every stop for the rest of the route