All of the following practices are dangerous to do while driving. Which of these is also illegal?

  1. Listening to music through headphones that cover both ears. ✓
  2. djusting your outside mirrors.
  3. Transporting an unrestrained animal inside the vehicle.

Answer: A. Listening to music through headphones that cover both ears.

Wearing a headset or earplugs in both ears while driving is illegal in California.

Why this is the answer

The handbook says you must be able to hear horns, sirens, motorcycles, and screeching tires that warn you of hazards. It then states plainly that wearing a headset or earplugs in both ears while driving is illegal. Headphones covering both ears fit that description, so that practice is not just risky, it breaks the law. The other listed habits may be unwise, but the handbook does not call them illegal.

Why the other answers are wrong

Remember it

If both ears are blocked, you cannot hear the siren coming — keep at least one ear open to the road.

Official handbook: California Driver Handbook (DL 600), Section 5: An Introduction to Driving, p. 9

Explanation drafted with AI (deepseek-flash) from the official handbook passage cited above, then checked automatically and by a second model on 2026-10-23. Always confirm with the official handbook.