A driver of a registered motor vehicle must adhere to which regulation concerning U.S. Forces POV license plates?

Answer: C — License plates must always be firmly attached

The requirement that license plates must always be firmly attached is vital for several reasons. Firstly, secure placement ensures that the vehicle remains compliant with U.S. Forces regulations, which maintain safety and accountability on the roads. Loose license plates can lead to them falling off while driving, potentially creating hazards for other drivers and resulting in penalties for the vehicle owner. Additionally, firmly attached plates ensure that they are clearly visible and easily readable, which is critical for identification by law enforcement and other officials. Given these factors, the necessity of having license plates securely affixed underscores their importance in maintaining order and safety in the use of motor vehicles within the U.S. Forces framework.