Which of the following is a requirement to maintain a Texas CDL?

Answer: C — Pass a vision test at renewal

To maintain a Texas CDL, passing a vision test at the time of renewal is a necessary requirement. Vision tests ensure that drivers retain adequate eyesight standards, which is critical for safe operation of commercial vehicles that require a CDL. The Texas Department of Public Safety mandates this test to safeguard both the driver and the public, ensuring that drivers can see clearly enough to navigate the roads safely. Other requirements may not be necessary at every renewal cycle. For instance, while defensive driving courses can be beneficial and sometimes required after certain violations, they are not a standing requirement for CDL renewal. An annual driving test is not a standard requirement either; periodic re-testing varies by individual circumstances. Likewise, purchasing insurance is essential for operating a vehicle but is not specifically tied to the CDL renewal process itself. Therefore, passing the vision test stands out as a definitive requirement while maintaining a Texas CDL.