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.

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.

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.

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.

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.