Gerri says that spiders use their fangs for the same purpose that crustaceans use their claws. Alana
disagrees and says that spiders use their fangs for the
same purpose that centipedes use their claws.

weathering - colorado river carves land in arizona to form the grand canyon. cracks form in a sandstone wall surrounding a house. a marble statue near the science museum is changing color due to rainfall

erosion - after a rainstorm, soil and rock piees litter the roadways. the sand dunes in the sahara desert are changing shape.

here's your answer.

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