X:
- Proposed design would allow for the lowest electricity rates
→
If we agree that we have no choice but to approve construction of a new plant, the proposed design must be the one we endorse
Y:
- Plant would damage community's air quality that the benefit of lower rates would be outweigh
→
(There is reason to be skeptical of the proposed design)
Now Y never explicitly says that conclusion, but from the tone of the passage, we can certainly infer it. It looks like they disagree that - IF there has to be a plant constructed - then it must be the proposed design. Notice how X very explicitly says that it "must be" this design while Y is very skeptical of the design as he appeals to the "obligation not to lower the quality of life of our community."
(A) This is kind of a tricky one. However, it is very unclear as to whether or not a new building should be built in the first place, let alone them recommending it. X seems to not want to build the plant in the first place ("if we agree that we have no choice but to approve construction...") while we don't really know how Y feels. In addition, it doesn't look they are arguing over IF the plant should be built but WHAT KIND of plant should be built, if it has to be built that is.
(B) We know nothing about improving the quality of life. We know that Y believes that they have a duty not to lower the quality of life but we don't know if this has anything to do with improving the quality of life.
(C) They probably both agree on this to some extent but they simply are not arguing over this fact. They are arguing over what design should be executed if the plant is to be built.
(D) Ah yes! It starts out really well with the "IF the plant is to be built" which is important to note (because they both don't sound too crazy about building it in the first place). Then it says that they disagreeing over whether the council should endorse a plant of the type in question. This makes sense! As I said, X seems to agree while Y implies disagreement.
(E) They probably both agree on this. We know that X stands by this assertion and Y never explicitly talks about it. Either way, they are not arguing about this factoid.