Logical ReasoningDifficulty: Hard

PT109 S3 Q18 Explanation

Studies have shown that photosynthesis,

A free, expert breakdown of this official LSAT Logical Reasoning question.

TopicsParallel Flaw

Keep going in LSAT Lab

  • Save & drill this skill — build targeted practice sets from questions like this one

  • Video walkthroughs — watch every question solved step by step

  • 81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

Free to start

Full official LSAT questions are available through LawHub. This page provides LSAT Lab's explanation, strategy, and review tools without republishing the full official question.

Stimulus

Studies have shown that photosynthesis, the process by which plants manufacture life-sustaining proteins from sunlight and carbon, is actually intensified if the level of carbon dioxide in the atmosphere is increased. Since carbon dioxide levels are increased by the burning of fossil fuels and by other human industrial activities, it to agriculture and those of us who depend upon it.

What this question is testing

Parallel Flaw

Your task

Break the argument into its conclusion and evidence, then do exactly what the question stem asks with that structure.

Common trap

Answers that sound relevant to the topic but don't connect to the argument's actual reasoning.

Winning move

Predict what a right answer must do, then test each choice against the conclusion-evidence gap.

Reading along? Open the full official question in LawHub — we show a fragment here and keep the reasoning in our own words.

The question
18.

The flawed reasoning in the argument above is most similar to that in which one

Answer choices

  1. Trap14% picked this

    Because a high fiber diet has been shown to be more healthful than a low fiber diet, a diet in which foods with a

  2. Correct69% picked this

    Because exercise has been shown to prevent a number of diseases, injuries, and other human ills, clearly no harm, and a lot

    Why this is right

    Answer B is correct.

    Skill tested: Parallel Flaw · how this choice captures the argument's function is the move to repeat next time.

  3. Trap2% picked this

    Consistently consuming more calories than one expends inevitably leads to excessive weight gain, so if one wishes to avoid the health problems associated with

  4. Trap5% picked this

    It has been shown that one can obtain more vitamins and minerals from fresh fruits and vegetables than from processed fruits and vegetables. One

  5. Trap10% picked this

    Excessive use of penicillin tends to increase one’s susceptibility to penicillin-resistant infections. The best policy, therefore, is to avoid using penicillin, thereby strengthening the

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill
LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free