Answer:
d. therefore
Explanation:
you clean your room therefore you can have the last piece of chocolate cake
In composition, unity is the quality of oneness in a paragraph or essay that results when all the words and sentences contribute to a single effect or main idea. Also called wholeness.
For the past two centuries, composition handbooks have insisted that unity is an essential characteristic of an effective text. Professor Andy Crockett points out that the "five-paragraph theme and current-traditional rhetoric's emphasis on method reflect further the expediency and utility of unity." However, Crockett also notes that "for rhetoricians, the achievement of unity has never been taken for granted" (Encyclopedia of Rhetoric and Composition, 1996).
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.
Can you give me the passage i can then answer your question
