Under Commercial Motor Vehicles Level I, the prohibited BAC range is 0.04 to 0.06.

• A. 0.02 - 0.04
• B. 0.06 - 0.08
• C. 0.04 - 0.06
• D. 0.08

Answer: (C)

The main idea is that for commercial driving, alcohol affects safety at relatively low levels, and there’s a defined range used in Level I training to indicate prohibited use. In this context, the range from 0.04 to 0.06 BAC is presented as the prohibited window. That means once BAC reaches 0.04, it’s already not permitted, and the range up to 0.06 is used to illustrate the extent of that prohibition in the training material.

So why this range fits best? The lower bound 0.04 marks the start of disqualification, and the range up to 0.06 stays within the commonly discussed impairment band in Level I materials. The other options either sit below the threshold (not prohibited), or lie outside the specified window (either higher than 0.06 or not aligned with the 0.04 starting point), so they don’t match the stated prohibited range.

For reference, real regulations require not operating a CMV with a BAC of 0.04 or higher, and 0.08 is the general non-commercial limit, but Level I materials often teach with the 0.04–0.06 range to emphasize that even moderate impairment is not allowed.