If you uncouple the dolly from the rear trailer, you should support the dolly with:

The landing gear (if equipped) or a block of wood.. Section 7.2: If the dolly has a support leg, use it. Otherwise, use a block of wood to

If you uncouple the dolly from the rear trailer, you should support the dolly with:

ANSWER BREAKDOWN
  • A. Correct. If the dolly has a support leg, use it. Otherwise, use a block of wood to keep the tow bar off the ground.
  • B. Incorrect. "Your hands." is not correct. If the dolly has a support leg, use it. Otherwise, use a block of wood to keep the tow bar off the ground.
  • C. Incorrect. "The air lines." is not correct. If the dolly has a support leg, use it. Otherwise, use a block of wood to keep the tow bar off the ground.
  • D. Incorrect. "The third trailer." is not correct. If the dolly has a support leg, use it. Otherwise, use a block of wood to keep the tow bar off the ground.