My reasoning in choosing C was that something being Hierarchical was not sufficient for concluding anything. It's the necessary component in the argument. But I guess something could be concluded, just not with what we've been given..

Been trying to understand this concept for 9 months and JY just made it all make sense in 8 minutes and 13 seconds...

404 thought process not found

Wow I was way off. I was focused on the level of understanding: fully/completely vs. properly. I really liked AC E but went with D (I know, let the booing commence) because E using such strong language as "understand completely" seemed too far from the premise.

At first I thought of C more as "we don't know the percentage of gasoline in gasohol so even if we're burning more gasohol than we would have gasoline on its own, we still might not necessarily be consuming more gasoline as a whole" but this is still irrelevant because regardless, this choice does not strengthen the argument. When using the trick of reading the argument and inserting "and" before each answer choice to see if it strengthens that argument, this one doesn't hold up.