Supervisor: I agree with your overall conclusion, but disagree about one point you make, since the latest closed furnaces are extremely fuel-efficient.
Speaker 1 Summary
The plant manager says that switching to a new copper-smelting process would be expensive and unprofitable. How do we know? First, the new equipment is expensive. Second, the new process costs more to run. This second point is supported by an explanation that the new process requires cooling then reheating copper (making it a sub-conclusion).
Speaker 2 Summary
The supervisor disagrees with the plant manager that the new process has higher running costs. This isn’t explicitly stated, but is implied by the support the supervisor gives: the new process is very fuel-efficient. We can infer that this supports a disagreement about the running cost because it would allow savings on fuel.
Objective
We need to find a point of disagreement. This is the claim that the new process costs more to run: the plant manager agrees, but the supervisor implicitly disagrees.
A
whether the new copper-smelting process releases less sulfur dioxide gas into the atmosphere than the current process
The plant manager agrees with this claim, but the supervisor never expresses an opinion. The supervisor’s argument is unrelated to sulfur dioxide emissions, so we can infer that the supervisor accepts the plant manager’s claim on this point.
B
whether the new copper-smelting process is more expensive to run than the current process
The plant manager agrees that the new process is more expensive to run, but the supervisor’s argument indicates disagreement. This isn’t explicitly stated, but the supervisor provides support for the implied conclusion that the new process isn’t more expensive to run.
C
whether the new process should be adopted in the copper-smelting plant
Neither speaker expresses an opinion about this. It may be tempting to assume the speakers agree on this because the new process would be unprofitable, but we don’t know how much they care about sulfur dioxide emissions. Either way, the speakers don’t disagree on this point.
D
whether closed copper-smelting furnaces are more fuel-efficient than open furnaces
The supervisor agrees with this claim, but the plant manager never expresses an opinion. The supervisor uses this as support for a disagreement with a single point the plant manager makes, but we don’t know what the plant manager thinks about fuel efficiency.
E
whether cooling and reheating the copper will cost more than moving it in molten form
The plant manager agrees with this claim, but the supervisor doesn’t indicate an opinion. The supervisor’s argument doesn’t dispute that cooling and reheating the copper costs more, just that the overall cost of running the new process is greater.