Q7 - Late blight is a disease affecting

[ohthatpatrick]

Question Type:
Match the Reasoning

Stimulus Breakdown:
Conclusion: Late blight must be caused by a copper deficiency in the tomato plants.

Evidence: Late blight causes blue-grey patches to appear on tomato leaves, and copper is an effective treatment for this condition.

Answer Anticipation:
They've done this type of argument before:
If a certain treatment works, then the condition must have been caused by a lack of that treatment.

Sounds crazy if you match it up with real life: "Aspirin effectively got rid of my headache. Thus, my headache must have been caused by an aspirin deficiency."

Correct Answer:
D

Answer Choice Analysis:
(A) Since radiation can be effective treatment for cancer .. [it should say:] cancer must be caused by a deficiency in radiation.

(B) The premise and conclusion are switched. The original is "Treatment --> Cause", and this is "Cause --> Treatment".

(C) Like (B), this is putting "Cause" into the premise.

(D) Holy crap! Haha. This is a lot like my example. YES, this seems to follow the original.

(E) Nope. Like (B) and (C), this is putting "Cause" in the premise.

Takeaway/Pattern: Even if we don't understand the flaw here, as long as we spy the structure of "If X can be used to treat Y, then Y must be caused by X." we can move quickly towards (A) and (D), and quickly from there to (D).

#officialexplanation