The analysis on the question does a poor job of explaining the answer. I also think the question itself is quite poor, but by POE A is perhaps more reasonable than C.

"but the stimulus text also cautions against eating too much fat because “fat in one’s diet is generally unhealthy.”"

This is objectively untrue. The dietitian absolutely does not caution against eating too much fat. This statement seems more like a concession (I accept that fat is generally bad, BUT we need it to process vitamin A). In my mind, this constitutes "undermining" the claim which is why I picked C. I knew that C was likely to be incorrect because of the word "completely" and that "undermine" might be a stretch, but I was unwilling to commit to any of the other answers.

Upon reviewing this for a while I think you can stretch the stimulus enough such that A can kind of make sense, but it is, at best, intentionally misrepresenting the actual meaning of the statement.

A more accurate answer A would look like:

"It is a generalization that, if heeded, could lead someone to adopt a dietary practice that the dietician provides a reason for not carrying to the extreme".

The statement is not mentioned as a reason for adopting a dietary practice. That simply does not follow from the stimulus, and I think it is part of why this question gave me a lot of trouble. A is a huge logical leap/unsupported inference. I wonder if the LSAT writers truncated the stimulus more than normal here and left a key part of it out.

@SriDaggumati

If people failed to notify the post office that they moved into the city, then we would expect the total number of household moving into the city to be underreported. This weakens the argument.

@LenyGrunis I thought this as well but the cool thing about this argument is that Walt having the Genie+ pass is not actually relevant at all to the conclusion.

You can remove the Genie+ Pass from your line of reasoning entirely.

1. Those (members) who have offered ten goats' worth of propitiations to Mickey Mouse can download their Genie+ pass via the Disney app.

2. All other members must prostrate themselves before Goofy's altar in the Magical Kingdom.

3. Walt is a member of the Disney vacation club.

Therefore, Walt must have offered the requisite propitiations to Mickey Mouse.

The Genie+ Pass is actually irrelevant here. I got caught up on this argument originally because I felt like there was a logical leap that the Genie+ fast pass is the same as the Genie+ pass in the argument

Why did this terminology change? Could an amusement park not have both a Fast pass and a pass? Could Walt have had the Genie+ Pass BEFORE he became a member?

But then I realized that that the rest of the statements are sufficient without even considering the Fast pass!