Please help me what's the answer

Which of the following are causes of coastal erosion? check all that apply. beach grasses and other plants trap windblown sand. wave action carves away the coastline. groundwater under pressure is forced to earth’s surface. artificial structures stop the natural flow of sand along the coast. underground caves collapse as bedrock is dissolved.

What feature of cell theory is best demonstrated in the image

Ineed to know why d is the correct answer asap