Final answer:
To qualify for a commercial driver's license, you must take a vision test, be in good physical health, and take a knowledge and road test, including a pre-trip vehicle inspection, so the correct answer is 'All of the above'.
Step-by-step explanation:
To qualify for a commercial driver's license (CDL), there are several requirements you must meet. These include:
- Take a vision test, to ensure that you can see well enough to drive safely.
- Be in relatively good physical health, to handle the demands of commercial driving.
- Take a knowledge test, a road test, and conduct a pre-trip inspection of your vehicle, to demonstrate your understanding of commercial driving rules and your ability to operate a commercial vehicle safely.
All of these criteria are necessary to ensure that only qualified individuals are permitted to operate commercial vehicles, which can be much larger and more complex than regular passenger vehicles. Hence, the correct answer is d. All of the above.