It's the idea of "reframing" what you are refuting so it is easier for you to refute. It is a huge fallacy.

A drastic example would be something like

John: I don't like ice cream. Therefore, at least one person in my family does not like ice cream.

Michael: You are wrong in saying no one in your family likes ice cream, because I have spoken to your brother, and he said he likes ice cream.

Michael is not really attacking what John side. I think of as creating a parallel universe that is similar to what was said, but not really representative of it. Michael would be correct in saying that it is wrong to say that no one in John's family likes ice cream, because his brother does. But, this is not what John said at all! He said "at least one person", right?

So it is an incorrect way of reframing what someone is saying, to make it easier for you to dispute it.

Answer D describes exactly that

I think for me it has been for helpful to think in terms of sufficiency/necessity than in terms of PSA. The idea is that sufficient assumptions absolutely guarantee the conclusion of the stimulus to follow in a valid way.

Try to ask yourself for each of the answer choices what answer, by itself, makes the argument absolutely airtight?.

It is similar to strengthening questions in a way (?). Try to strengthen the argument. But, even more. Try to make the argument completely valid.

I hope that is helpful!

From my understanding, it is not simply about being willfully ignorant, but the real relevant piece of information that E provides is that the description was intentional, "merely in order to increase its auction price". The fact we were missing to make sure the application made sense for this case was "if such a description was a deliberate attempt to mislead bidders". And you can reasonably assume that if the auction house made no effort to make sure their claim was correct, and still included in the description "merely in order to increase its auction price", it has indeed been a deliberate choice in order to mislead the bidders. I hope this makes sense :)