To measure wind or gas current
It would be D Chickamauga
Hope this helps!
As far as largest, its the pacific plate. Smallest has two answers: Juan De Fuca, off the coast of the American Northwest, is the smallest major plate, but of all plates, major and minor, the smallest is the Galapagos microplate.
Answer: b
Explanation: Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock