Question

The core limitation with the last line of the passage is that it:

• A. assumes that all ancient societies required identical proportions of tin and copper in their bronze alloys.
• B. relies on the assumption that corrosion has not significantly affected the geochemical analysis of ancient tin ingots.
• C. underestimates the possibility that ancient societies may have substituted other materials for tin when necessary.
• D. presumes, without sufficient evidence, that no other tin sources besides those mentioned could have met the demand.
• E. confuses the presence of rich tin deposits with the certainty that those deposits were actively mined and exported at scale.

Hint:

When an argument concludes something is necessary because all known alternatives are insufficient, the key assumption (and potential flaw) is that the list of alternatives is complete. The argument is weakened by the possibility of an unknown alternative.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept
This question asks for a "limitation" or flaw in the passage's conclusion (the "last line"). The passage likely concludes that Britain was a major source of tin *because* other known sources were insufficient. The flaw would be in assuming that the "known" sources are the *only* possible sources.
Step 2: Detailed Explanation
Let's reconstruct the likely argument: 1. The Bronze Age Mediterranean needed a huge amount of tin. 2. Known tin sources in Central Asia were X, Y, Z. 3. Evidence shows British tin was traded. 4. (Last Line Conclusion): Therefore, Britain must have been a major supplier, as sources X, Y, Z were not enough. The limitation in this logic is the jump from "known sources were not enough" to "therefore Britain was a major supplier." This leap contains a hidden assumption. Let's analyze the options:

(A), (B), (C) are potential minor issues but likely not the "core limitation." The argument is about the large-scale origin of tin, not the specifics of alloys, corrosion, or substitution.
(E) is a valid point about geology vs. history, but it might not be the flaw in the *final concluding line* specifically.
(D) perfectly identifies the central flaw. The argument concludes that Britain was essential by appearing to eliminate other possibilities. However, it only considers the currently *mentioned* or *known* sources. The argument's weakness is that it "presumes, without sufficient evidence, that no *other* tin sources... could have met the demand." The existence of a large, yet-to-be-discovered tin source elsewhere would completely undermine the conclusion.
Step 3: Final Answer
The core limitation is that the argument draws a strong conclusion from incomplete knowledge, assuming that the currently identified ancient tin sources are the only ones that ever existed. Option (D) captures this flawed presumption.