How does the Electronic Stability Program (ESP) intervene when detecting imminent rollover or severe loss of directional control in a bus?

1. It selectively brakes individual wheels and reduces engine torque to stabilize the vehicle's trajectory
2. It instantly dumps all compressed air from the suspension to drop the chassis onto the axle bump stops
3. It applies maximum spring-loaded parking brakes on all axles simultaneously
4. It locks the steering wheel in the straight-ahead position