The 'Crack-the-whip' effect (rearward amplification) is most dangerous for:

The rear-most trailer (last trailer).. Section 6.1: When you make a quick lane change, the crack-the-whip effect increases as you go back.

The 'Crack-the-whip' effect (rearward amplification) is most dangerous for:

ANSWER BREAKDOWN
  • A. Incorrect. "The tractor." is not correct. When you make a quick lane change, the crack-the-whip effect increases as you go back. The rear trailer is most likely to turn over.
  • B. Incorrect. "The first trailer." is not correct. When you make a quick lane change, the crack-the-whip effect increases as you go back. The rear trailer is most likely to turn over.
  • C. Correct. When you make a quick lane change, the crack-the-whip effect increases as you go back. The rear trailer is most likely to turn over.
  • D. Incorrect. "A bobtail." is not correct. When you make a quick lane change, the crack-the-whip effect increases as you go back. The rear trailer is most likely to turn over.