Why should you leave sufficient space in front of you when stopped behind a large vehicle, especially when facing uphill?

• Because when the driver releases the brake, the vehicle may roll back
  Explanation:

  "Leave ample space when stopped behind a large vehicle, as it may roll back when the driver releases the brakes after stopping."
• Because the large vehicle will take time to accelerate again
• Because it may cause your vehicle to stall
• Because it causes a traffic jam