If you must drive on a slippery road, you should not use:

The engine brake (retarder).. Section 2.13: Do not use the engine brake (retarder) on slippery roads, as it can cause the drive wheels to

If you must drive on a slippery road, you should not use:

ANSWER BREAKDOWN
  • A. Incorrect. "The defroster." is not correct. Do not use the engine brake (retarder) on slippery roads, as it can cause the drive wheels to skid.
  • B. Correct. Do not use the engine brake (retarder) on slippery roads, as it can cause the drive wheels to skid.
  • C. Incorrect. "The headlights." is not correct. Do not use the engine brake (retarder) on slippery roads, as it can cause the drive wheels to skid.
  • D. Incorrect. "The windshield wipers." is not correct. Do not use the engine brake (retarder) on slippery roads, as it can cause the drive wheels to skid.