The correct answer is C) the difference between the heights of high and low tide. The range of tide refers to the vertical distance between the high tide and low tide water levels at a given location. This is the difference in height between the high and low tides, not the distance the tide moves out from the shore (A), the maximum depth of the water at high tide (B), or the duration of time between high and low tide (D). The range of tide is an important factor in navigation and coastal planning, as it determines the minimum and maximum water depths that vessels and structures need to accommodate. The other answer choices do not accurately describe this key tidal characteristic.