What is the primary distinction between standard gauge and narrow gauge tracks?

The primary distinction between standard gauge and narrow gauge tracks lies in their measurements. Standard gauge tracks have a width of 4 feet 8.5 inches, which is recognized as the industry standard. In contrast, narrow gauge tracks are defined as having a width that is less than this measurement. The width difference affects various operational aspects, including train stability, speed, and the types of trains that can run on these tracks.

Understanding the implications of gauge width is crucial for rail operations. Standard gauge is typically used for mainline railroads and is better suited for high-speed trains and heavy freight traffic, while narrow gauge is often found in specific applications such as mountainous terrain or certain regional systems where space constraints or operational needs dictate its use. This distinction is fundamental to rail infrastructure and operations, making option C the correct and complete explanation of the difference between standard and narrow gauge tracks.