In Arkansas, it is illegal to drive or be a passenger without:

Answer: A — valid driver's license

In Arkansas, it is illegal to drive or be a passenger without a valid driver's license because having a driver's license is a legal requirement to operate a motor vehicle on the roadways. A driver's license acts as proof that the individual has passed the required tests and is deemed capable of operating a vehicle safely. Therefore, driving without a valid driver's license is against the law in Arkansas. Options B, C, and D are not directly related to the requirement of having a valid driver's license. While having a working horn, proper headlights, and wearing a safety belt are essential for safe driving, the primary legal requirement to drive in Arkansas is possessing a valid driver's license.