If your articulated vehicle is equipped with a trailer hand brake (trolley valve), why should you NOT use it to correct a trailer jackknife?

1. Applying the trailer hand brake will cause the trailer wheels to lock up even further, worsening the slide and jackknife
2. The trolley valve only operates the front steering axle of the tractor
3. The hand valve causes the fifth wheel slider rail to unlock automatically
4. It will shut off the engine due to a sudden drop in fuel line pressure