No live commentary for the RC?

This is the conditional chain presented in the stimulus:

good meals --> good food --> good soil --> good farming --> cultural values etc

So A can be inferred; good meals depends on both natural conditions (good soil) and cultural ones (all that cultural values stuff).

But maybe you can have mediocre food with bad soil. And if so, you can possibly produce a good meal with bad soil, since mediocre food can possibly produce a good meal.

Well, it doesn't help to think in shades of gray like that with conditional logic. There is no mediocre, there are only "good" and "not good" (i.e. bad).

Good meals cannot be produced from "not good" food, you are mistaken about that.

I mean, it makes sense if you accept the conditional chain above right? If so, then you just need to revisit conditional logic and make sure you understand it better.