Which of the following conditions can disqualify a commercial driver from certification?

Severe uncontrolled hypertension is a serious medical condition that can significantly impact a driver's ability to operate a commercial vehicle safely. High blood pressure can lead to various complications, such as cardiovascular disease or stroke, which may incapacitate the driver and increase the risk of accidents on the road. Because commercial drivers must maintain a level of health that ensures they can navigate complex driving situations safely, severe uncontrolled hypertension is grounds for disqualification from certification.

In contrast, seasonal allergies, specific ear infections, and mild astigmatism, while they can affect a person's health or comfort, do not typically present the same level of immediate threat to driving safety as uncontrolled hypertension. Seasonal allergies may cause discomfort but are generally manageable and do not severely impair driving ability. Similarly, while an ear infection might temporarily affect balance or hearing, it can often be treated effectively without long-term impacts. Mild astigmatism is a common vision condition that can usually be corrected with glasses or contact lenses and does not inherently disqualify a driver if their vision can meet the required standards.