The correct option is 2° to 5°.
Explanation
The ocean floor is divided into distinct relief features based on depth and gradient. The continental slope is the zone of steep descent connecting the continental shelf to the deep ocean floor (specifically the continental rise or abyssal plain). It marks the structural boundary between the continental crust and the oceanic crust.
Detailed Analysis:
- The continental shelf is the shallowest part of the ocean floor, characterized by a very gentle gradient, typically 1° or less.
- The continental slope begins at the shelf break, where the gradient increases sharply. The typical gradient of the continental slope ranges between 2° and 5°.
- While the average gradient is within this range, it can vary significantly depending on the location. Slopes off stable coasts may be gentler, while those near active plate margins or deep trenches can be steeper.
- Options suggesting 10°-15° or 45°-60° represent extremely steep inclines found only in specific, localized underwater canyons or trench walls, not the general continental slope.
Key Takeaway:
The continental slope is defined by a distinct increase in gradient (averaging 2° to 5°) compared to the nearly flat continental shelf, serving as the transition zone to the deep ocean basin.