Your response is a lifesaver. Thank you. 🙏

Here are my thoughts (I chose B):

• The supervisor agrees with the plant manager's conclusion: adopting the new process [which encompasses (1) installing the new equipment and (2) running the process/operating using that new equipment] will cost a lot of money, and produce no profit.

• However, the supervisor's objection is related to the plant manager's sub conclusion/premise that the new process will be more expensive to run/operate vs the old process. By stating that the closed furnaces (a part of the new copper-smelting process) is more fuel-efficient, the supervisor is implying that it's less expensive to run the new process than the plant manager believes.

• Thus, the supervisor is (subtly) expressing skepticism that the new process is more expensive to run than the old process. And B is the closest answer choice to align/articulate that skepticism.

Hope this helps!

Likewise. The disagreement was pretty explicit for a question type that asks us to look out for subtle objections.