The subordinate clause here is A, "as the layers of ash slowly compressed". Subordinate means that it cannot exist on its own, it has to be a part of the main, independent clause.
Answer:
see below
Explanation:
It can change the meaning when one goes back and understands the time, place, and perspective from when the book was originally written.
I say "a circus elephant" because the information in the text clearly describe "a circus elephant."
