What does tidal range refer to?

Tidal range is defined as the difference in height between low water and high water during a tidal cycle. This measurement reflects the vertical distance between the lowest point (low tide) and the highest point (high tide) that the sea reaches along the shoreline. Understanding tidal range is essential because it affects coastal ecosystems, navigation, and marine activities, as well as the physical environment of coastal regions.

The other options do not accurately represent what tidal range is measuring. The average level of the ocean's surface refers more to the typical elevation of sea level, while the total volume of ocean water pertains to the overall amount of water in the oceans. The average temperature of ocean water is related to environmental conditions and climate but does not correlate with the concept of tidal range. Thus, the definition of tidal range specifically focuses on the measurement of tidal heights, making the correct answer clear.