Method of Reasoning—AP. The correct answer choice is (C)
This author of this stimulus discusses the trade route between China and the West, and concludes that it wouldn’t be surprising to learn that it was opened centuries or millennia before 200 B.C., the widely-accepted date. The first statement of this stimulus provides the author’s conclusion. The rest of the stimulus provides premises for that conclusion: the same things that made the Great Silk Road attractive as a trade route after 200 B.C. were present during the early emigration to China one million years ago. If there was migration, there just as easily could have been trade along the same route:
- Premise: The route that was valuable to China and the West would also have been valuable to those traveling to China from Africa and the Middle East.
Premise: The immigration from Africa and the Middle East began at least one million years ago.
Conclusion: It would not be surprising to discover that the trade routes between China and the West were opened well before 200 B.C.
The question stem asks what function the statement about the migration to China from Africa and the Middle East one million years ago serves in the passage. This is a premise that is offered in support of the main conclusion.
Answer choice (A): The conclusion in the stimulus is that it would not be surprising, not that it definitely occurred. This quote is not intended to provide “conclusive” evidence, so this choice is a safe elimination.
Answer choice (B): Intermediate conclusions can serve as premises for the main conclusion, but since this piece of information is provided as a fact, unsupported by other premises, this cannot be properly characterized as a subsidiary conclusion.
Answer choice (C): This is the correct answer choice. With migration from the Middle East and Africa to China, early trade between these two regions would seem a reasonable possibility. This migration occurred one million years ago, far earlier than the trade routes were believed to have been established.
Answer choice (D): The stimulus does not make a distinction between respective routes to Africa and the Middle East, so this answer choice is incorrect.
Answer choice (E): Since the referenced statement does not represent the main conclusion of the stimulus, this answer choice is incorrect.