Which answer choice most appropriately fits in the blank? cause: erosion and weathering break down rocks into smaller pieces. effect:

a. then, the waves hit rocky cliffs and break the rocks apart.
b. then, the small rock pieces build up and create new rock.
c. then, the rocks and pebbles carried by the organisms to carve out canyons and gorges.
d. then, the wind, sand, and pebbles beat against the rocks and the rocks break