When emergency braking on a slippery surface in an older vehicle WITHOUT an ABS system, what braking technique should be employed to prevent wheel lockup and maintain steering control?

1. Stomp the pedal to lock all four wheels permanently into a skid
2. Use cadence/threshold braking (intermittent pumping / 点刹), repeatedly applying pressure to threshold and releasing before wheels lock up
3. Pull the handbrake lever up and down rapidly while holding accelerator
4. Put transmission in neutral and take hands off steering wheel