Which of the following is NOT one of the physical qualifications for drivers?

The correct choice regarding physical qualifications for drivers is one that states there should be "no loss of hearing in both ears." This is not an absolute requirement as hearing can vary among individuals. The FMCSA requires that drivers must be able to perceive a "forced whispered voice" from a distance of five feet or have a hearing aid to meet hearing standards. Thus, complete hearing loss in both ears does not disqualify a driver, provided they can meet the minimum requirements.

The other options highlight critical qualifications. The absence of mental or psychological disorders that could interfere with the safe operation of a vehicle is essential for ensuring that drivers maintain cognitive functions necessary for driving. Additionally, insulin-dependent diabetes mellitus can be disqualifying if it is not well-managed, so the regulation explicitly forbids those whose condition isn't controlled adequately. Lastly, the requirement for distance vision of 20/40 in each eye ensures that a driver can see and react to road conditions and signs effectively.