Yeah, I chose E too. I think the main thing to focus on for this one is that the last sentence is the conclusion, and the conclusion itself notes that its premises (that monetary value is needed to compare costs and benefits, but that monetary value also cannot be assigned without using costs and benefits) get in each other's way.

I picked D too! Reviewing it, I think you can initially eliminate it because it says the blame is placed on the incumbents, not the parties. I agree with the previous person's comment in that the idea of the challenger is not really discussed in the stimulus, though I disagree with the is/ought. This question choice is about finding a principle (an "ought") to explain an action/event (an "is"). That being said, those distinctions are important to pay attention to, but they depend on the question type as well.

I understood why D could be the answer, but I was having trouble ruling out A since both answers deal with genetics. Auntie2020's response helped though, since although A does have to do with how genetics can factor in (and seems too strong), D goes directly against the premise by making genetics be the only determinant of schizophrenia. A could very well be true, because perhaps both twins did have the genetic predisposition, but only one got the damage that then enabled schizophrenia to emerge, and so genetics determines the initial susceptibility, but environmental factors determine whether or not the person develops it.

Thank you! Good luck everyone!