Answer:
D. They find more things that are not understood
Explanation:
After discovering something, scientist tend to find something related that sparks their curiousity.
The answer for your question is A.
Older oceanic crust, which is more dense than continental crust, has long since been recycled in the process of subduction. Credit: U.S. Geological Survey. Plate tectonics shapes the surface of our planet, but it also runs much deeper: Plate movement is the surface expression of convection in Earth's interior.
Answer:
symbiosis.
Explanation:
The term that you are referring to is symbiosis. (a symbiotic relationship)
Symbiosis is a proximate and often long-term interaction between two or more different biological species.