Question

which is one piece of evidence of seafloor spreading?
fossil material
continent material
drilled core samples
ocean water samples

Explanation:

Drilled core samples from the ocean floor show that the age of the rocks increases with distance from mid - ocean ridges. This supports the theory of seafloor spreading. Fossil material and continent material are not specific evidence for seafloor spreading. Ocean water samples do not directly relate to the geological process of seafloor spreading.

Answer:

C. drilled core samples