Premise: Trade between northern and southern cities has stagnated. The cause is the lack of reliable methods of transportation.
Conclusion: To spur economic growth, we must build a freeway system that passes no more than five miles away from each city.
We are asked to find the option that most seriously weakens the reasoning.
That means we want a statement that shows:
Either the freeway is not necessary,
Or something else could solve the problem better,
Or the “5-mile distance” condition is unnecessary or irrelevant,
Or that the assumed cause (transportation issues) is not the actual or primary cause.
Option A:
Building a freeway system that passes as much as ten miles from each city would be sufficient to greatly increase trade between the northern and southern cities of the state.
This directly undermines the specific recommendation that it must be “within five miles.”
If a freeway 10 miles away is sufficient, then the added cost/effort to meet the 5-mile requirement may not be justified.
🔥 Strongly weakens the necessity of the proposed plan.
✅ Contender
Option B:
There are other, more important causes for the lack of trade between the northern and southern cities of the state in addition to a lack of reliable methods of transporting goods between these two groups of cities.
This challenges the causal assumption: That transport is the main issue.
If other, more important causes exist, then the freeway may not effectively solve the problem.
🔥 Strongly weakens the argument by undercutting the causal reasoning.
✅ Contender
Option C:
The state’s infrastructure budget is not currently large enough to finance the construction of a freeway system.
This brings in a practical constraint (budget), but does not directly weaken the reasoning behind why the freeway should be built.
It challenges feasibility, not the logic of the plan.
❌ Not a strong weakness of the reasoning itself — more of a financial barrier.
🚫 Eliminate
Option D:
Growth in the commercial traffic between two groups of cities is most often associated with the closeness of the transportation system with the cities.
This actually strengthens the reasoning — that closeness of the freeway helps trade.
❌ This supports, not weakens, the argument.
🚫 Eliminate
Option E:
The reliability of existing methods of transporting goods between the northern and southern cities of the state can be improved to some extent without building a freeway system.
This offers an alternative solution — improve current methods.
It weakens the idea that a new freeway is necessary, though it doesn’t fully negate the argument (depends on how much trade improves).
✅ Mild to moderate weakening — suggests freeway may not be the only/best solution.
✅ Still a weaker contender than A or B.
✅ Best Answer: A
Because it directly challenges the necessity of the specific “within 5 miles” freeway, showing that a less extreme (10-mile) version can achieve the same goal — thus undermining the core recommendation most precisely.
Final Answer: A ✅