When asking about the organization of the last paragraph, it's presumably a given to view the organization in context with the rest of the passage. I interpreted the question incorrectly and was solely focused on the organization of the last paragraph in isolation from the rest of the passage. I selected D as opposed to A because I thought that the last paragraph was introducing new information and therefore was introducing a new theory. I did not select A because D emphasized the introduction of new information when did not. May someone can explain in greater detail what makes D wrong? Is a hypothesis fundamentally different from a theory?

I thought that A was all encompassing of what the passage was about. When the passage asks what it is primarily concerned with assessing, is this asking about the conclusion or what the passage is about? I'm doing my best not to be too attached with my answer choices, but I spent a good amount time on the blind review (hours) and still selected the wrong answer choice. For whoever reads this, can they explain why A is not good answer choice and more over what the question is asking? Is it asking what the passage is about or what the author's concerns are regarding the information provided in the passage?

Note to self: Subsidiary and Subsequent are not synonyms.