What are the only mandatory regulations that must be followed during the examination?

The correct choice emphasizes the essential regulations mandated by the FMCSA for driver medical exams. Specifically, the items listed—vision, hearing, epilepsy, and insulin-dependent diabetes mellitus (IDDM)—are critical areas that must be assessed to determine an individual's fitness for safe driving.

Vision is crucial for operational safety, as drivers must be able to clearly see road signs, other vehicles, and pedestrians. Hearing assessments ensure that the driver can hear critical warning signals from other vehicles and surrounding environments, which is vital for maintaining safe driving practices.

Epilepsy is specifically monitored because seizures can lead to a loss of control while driving, presenting significant risks not just to the driver but also to the public. Individuals with insulin-dependent diabetes mellitus must be assessed to ensure their condition is managed effectively, as fluctuations in blood glucose could impact their driving abilities.

In contrast, general physical fitness standards, while important, do not specifically address the key areas that could directly affect a driver's need to operate a vehicle safely. Cardiovascular evaluations may be beneficial for overall health but are not part of the mandatory assessments required for the DOT physical exam. Thus, the focus on vision, hearing, epilepsy, and IDDM stands out as a comprehensive approach to ensuring that drivers do not pose a safety