Parallel questions have a highly regimented theory and approach – even if your core logical intuitions are very strong, following a routine process specifically built around the LSAT’s unique patterns will dramatically reduce the time and mental energy required to identify the correct answer. So review these lessons. They’re important.

In short, though, our approach will be to develop an abstract model of the stimulus’ argument, preserving the structure but not the subject matter, then take a shallow dip into the answer choices looking for structural mismatches. Usually that suffices to identify the correct answer, but sometimes we’ll need a deep dive to distinguish between the (usually just two) answer choices that remain after our shallow dip.

This question hinges on a short list of formal logic skills. Let’s lay them out on the table right now.

1: Whenever indicates a sufficient condition.

In every single answer choice, Premise 1 is worded in a simple “[All/Most/Some] Serious joggers can benefit from good running shoes” structure. Serious joggers comes first in both the sentence and the diagram.

Serious → Benefit

In the stimulus, Premise 1 is worded in the opposite way: “Jack’s dog howls whenever a train goes by.” Howls comes first, but it’s second in the diagram because the word “whenever” indicates a sufficient condition regardless of where in the sentence it appears.

Train → Howls

So Premise 1 looks different than its counterparts in the answer choices, but logically it matches up (except in (B) and (D), which are a “most” and a “some” claim, respectively).

2: “Some” claims are reversible.

The nature of the “some” relationship allows us to swap the terms around and retain its meaning: if some cats are pets, some pets are cats

Cats ←some→ Pets
Pets ←some→ Cats

Recognizing you can flip the wording of “some” claims is also critical to success in this question.

3: There’s only one way to draw an inference from a “some” claim

If you’re rusty on your valid formal arguments, now’s a great time to review. The only valid way to derive an inference from a “some” claim is to put some before all.

Pets ←some→ Cats → Conniving
validly gives you…
Pets ←some→ Conniving

Nothing else works.

Get ready to use all those skills, baby! Let’s diagram the argument. Here’s how it looks on a first translation from the English:

Premise 1: Train → Howls
Premise 2: Train ←some→ Wash
________
Conclusion: Wash ←some→ Howls

This argument works by putting some before all, but you have to make a few adjustments to see it clearly. Let’s swap the order of Premise 2’s terms and put it first:

Premise 2: Wash ←some→ Train
Premise 1: Train → Howls
________
Conclusion: Wash ←some→ Howls

There we go. If you like a nice pretty chain, it’s easy to make now:

Premise 1+2: Wash ←some→ Train → Howls

Our correct answer choice needs be a valid argument that puts some before all.