Official Solution:
The cobblestone streets in the old quarter of Castellonia provide urban planners and historians with an authentic representation of medieval street design. These streets have been preserved with minimal modern intervention, unlike many other historic city centers that have been updated or rebuilt.
Which of the following assumptions is the argument above making?
A. The buildings surrounding the old quarter of Castellonia are largely from the same era as the cobblestone streets.
B. There are no other city areas in Castellonia that have preserved their medieval street layouts.
C. Many modern urban centers have street designs based on principles developed in medieval times.
D. The cobblestone streets in Castellonia’s old quarter are more similar to their original medieval design than those in most other historic city centers.
E. The techniques used to preserve streets in Castellonia have not changed significantly over the centuries.
(A) Incorrect. We are not interested in the buildings, just street designs. Eliminate.
(B) Incorrect. We are not arguing about which city area in Castellonia are more preserved; our argument is specifically about the old quarter. We can eliminate this as well.
(C) Incorrect. We are not concerned with other cities adopting the principles but rather the argument around the preservation of streets to provide an authentic representation of medieval street design. Eliminate
(D) Correct Answer. This assumption is required for the argument to work. If the cobblestone streets in Castelloia’s old quarter are not more similar to their original design than in other cities, then there is no reason for us to study them as they would not be representative. Somewhat simple but subtle assumption.
(E) Incorrect. This is not a required assumption as techniques used to preserve streets are not covered (if these things even exist). We are not concerned with the preservation techniques, only the final product of unmodified design.
Answer: D