I believe JY's cost-benefit chart has the symbols in the incorrect positions#feedback

In the question stem, JY translated the "but" into "and". However, for (D), he translated the "but" as "or" - is that difference simply due to te "but" being in the sufficient vs necessary clause?

#help

Agreed, I also swapped the order because I placed the "only" statement as the necessary condition

#help

#help !

To a degree, when evaluating reasonability, aren't we incorporating personal knowledge in order to evaluate reasonableness? Where's the line between applying background knowledge and not here?

#help