The Marine cliffs are formed mainly due to:  A. Ocean Currents  B. Structure of Shall  C. Coast of Sea  D. Depth of The Ocean

Marine cliffs are primarily formed due to the structure of the shell (Option B). Here's a step-by-step explanation:

1. Marine cliffs are steep faces that are adjacent to the sea. They are formed by the erosive action of the sea waves.

2. The structure of the shell, or the geological structure of the land, plays a significant role in the formation of these cliffs. This is because different types of rocks have different levels of resistance to erosion.

3. For instance, if a coastline is made up of both hard and soft rocks, the sea waves will erode the softer rocks faster. This creates areas of land that jut out into the sea (headlands) and areas that are more recessed (bays).

4. Over time, the continued erosion of the softer rocks in the headlands can lead to the formation of cliffs.

5. Therefore, while factors like ocean currents and the depth of the ocean can influence the rate of erosion, it is the structure of the shell that primarily determines where and how marine cliffs are formed.