So far, your explanations have been great, and I'm satisfied with my purchase in general. However, could you please elaborate your explanation of answer choice (A). To me, it appears the logic is flawed, but in a different way than in the stimulus

(A) reads: RforO <--m-- L ----> P

This is not how it's characterized in your explanation.

Tom,

The Set you've purchased was created by Nathan Fox. He's a local LSAT guru here in the SF Bay Area, and we were lucky enough to get some of his content to feature in our App.

However, despite the fact that he scored a 179, and that his classes get rave reviews, it seems Nathan is human after all.

The explanation he gives for choice (A) is wrong.

Here's my take on choice (A). Choice (A) says:
1. L → P
2. For Most L: L → Run
THEREFORE: For Most P: P → Run

This fallacy is known as the "Undistributed Middle." Choice (A) takes the consequents of Premises 1 & 2 and assumes a relationship between the two--despite a lack of basis for the assumption.

This would be the same as saying:
1. All birds have wings.
2. Most birds can swim.
THEREFORE: Most things that have wings can swim.

It seems to me that Nathan has come up with a shortcut that works for this problem (“most” comes before the “all”). And his shortcut is pretty fast to use (this is important, as this problem took me some time). But it also seems his shortcut is faulty.

If I were faced with this question on the test, I'd probably have to diagram out choices (A) and (D), and then see which matches the passage.

Arcadia,

Thanks for the tip, this explanation makes the choice much more clear.

Thanks for your responsiveness! I really appreciate it!