Allright, so I see why C is the correct answer, but I still can't understand why B is incorrect

Quoting the explanation

"Consider if it were negated – facility in operating machines designed for use by non-experts is enhanced by expert knowledge of the machines’ inner workings. The fact that it is enhanced tells us nothing about the relationship between technical and traditional education. For all we know there is something else that enhances the ability to use machines even more that is associated with traditional education."

I understand this, but the prompt says "technological expertise would prepare students for tomorrow's job market NO better..."

NO being the key word - I'm thinking that if technological expertise prepares students any better at all to work these machines, the argument that it would prepare students "NO better" is wrong?

What I don't get here is why exactly C and D can't be right. The question stem says parents differ in their beliefs regarding rules / disciplinary structure - so I'm imagining a possible scenario where two parents both prioritize discipline above anything else, one subscribing to the Gerber method and one subscribing to the Ferber method (both made up, conflicting systems of disciplinary rules).

So I can see how Stephanie's reply addresses the general issue of how highly parents value discipline, but not the fact that 'any disciplinary structure in schools is bound to create resentment because it will contradict some parental approaches' - in which case B seems correct, because its just too general

I can also see how D would make sense with the exact same reasoning because other parents might be hippies without any discipline, a scenario Stephanie successfully counters, but still leaves different rules of parents with discipline as a high priority unaddressed - so D could be right because 'high on the list' is not specific enough to counter the argument.

I want to understand why my reasoning is flawed here.

How can you be sure (using this instance for example) that something is a main conclusion as opposed to a premise?

What caught me up on this one was the difference between 'shortly after' his death as the timeframe for the copy in the critic's response versus the 'at the time of his death' in the answer choice. It seems that often these answers make you look for the smallest difference to choose or disqualify them, and here its not taken into account. Is there a rule of thumb for this?