They are both on the end of the Pacific rim. They both have an above average number of volcanoes, and they are steeper and more narrow then other mountain ranges. This is a result of their both straddling and colliding continental plates and being on top of very active geological fault lines.
Answer:
Infrequent but highly explosive
Explanation:
At a subduction zone, the descending plate carries with it sediments containing water and carbon dioxide.
These substances are trapped as fluids at high pressure in the rising magma.
When they reach atmospheric pressure at the surface, they become gases that expand suddenly and explosively.
The answer is B. I believe that this is the answer because the barnacle is benefiting from the gray whale without harming, or affecting it in the process.