Which zone extends from dunes to the high tide line?

• A. Splash Zone
• B. Intertidal Zone
• C. Subtidal Zone
• D. Bathyal Zone

Answer: (A)

The key idea is how coastal zones are defined by tidal exposure and spray. The area from the dunes up to the high tide line is the splash zone (supratidal zone): it sits above the high tide line and is only wetted by wave spray, not by regular tidal immersion. This makes it distinct from the intertidal zone, which is between high and low tides and regularly wet, and from the subtidal zone, which stays underwater below the low tide line. The bathyal zone is a deep-ocean area far offshore, not part of nearshore landward zones. So the correct choice is the splash zone.