The subtidal zone is the area: Between low and high tide. Beyond the continental shelf.
Between the intertidal zone and the edge of the continental shelf.
Where pelagic organisms live.

can you make it bigger i can't see it

the sun creates it's own light, also gives light and life to bunch of stuff like plants,animals,humans etc.photosyntesis is the process of making food which needs sun,water,nutrients etc.

i'd have to say the answer is probable the second option "the geosphere interacting with the atmosphere"

to this answer it would be edge enhancement