Most heavy-duty vehicles use:

Dual air brake systems.. Section 5.2: Most heavy-duty vehicles use dual air brake systems for safety.

Most heavy-duty vehicles use:

ANSWER BREAKDOWN
  • A. Correct. Most heavy-duty vehicles use dual air brake systems for safety.
  • B. Incorrect. "Single air brake systems." is not correct. Most heavy-duty vehicles use dual air brake systems for safety.
  • C. Incorrect. "Triple air brake systems." is not correct. Most heavy-duty vehicles use dual air brake systems for safety.
  • D. Incorrect. "Hydraulic systems only." is not correct. Most heavy-duty vehicles use dual air brake systems for safety.