Final answer:
The UTM grid system's greatest advantage is the ease of determining distances due to its Cartesian coordinate system that maintains scale across zones, simplifying accurate distance measurement on maps.
Step-by-step explanation:
The greatest advantage of the UTM (Universal Transverse Mercator) grid system is B. Easy to determine distance. The UTM system divides the Earth into a series of six-degree longitudinal strips, or zones, each with its own central meridian. This system simplifies the process of calculating distances because it uses a two-dimensional Cartesian coordinate system to identify locations on the map. Distances between points can be measured more directly and accurately than in a system based on degrees, which must account for the curvature of the Earth.
The UTM system is especially useful for detailed mapping and land surveying where precise measurements are required. Unlike the latitude and longitude system, where lines converge toward the poles and distances between degrees of longitude change, the UTM system maintains scale across each zone, making it easier to calculate real-world distances without complex adjustments.