The trees always blossom in May if April rainfall exceeds 5 centimeter

KAPLAN OFFICIAL EXPLANATION

(A) Parallel Reasoning (Logical Flaw)

When a Parallel Reasoning argument contains Formal
Logic, translating the stimulus algebraically will make
it much easier to compare to the answer choices.
Translating the first two sentences of the stimulus, we
learn that one trigger (April rainfall in excess of 5
centimeters—we’ll call this “X”) causes two necessary
results: the trees will blossom in May (we’ll call this
“Y”), and the reservoirs will be full on May 1 (we’ll call
this “Z”). So in our formal logic notation, we can write
“If X → Y” and “If X → Z.” Our last sentence tells us
that since our reservoirs aren’t full (in other words, “no
Z”), the trees will not blossom (in other words, “no Y”).
So our final formal logic statement would be “No Z, so
no Y.” The absence of one result does not guarantee
the absence of the other, so here is the flaw that we’re
looking for in the answer choices. Armed with our
algebraic notation, we can more easily find a match.
(A) The first two sentences of (A) give us two
necessary results following from the same trigger—
just like the stimulus. Let “garlic in the pantry” equal
“X,” “garlic still fresh” equal “Y,” and “potatoes on the
basement stairs” equal “Z.” Then we have “If X → Y”
and “If X → Z.” Our last sentence says that the
potatoes are not on the stairs (“no Z”), so the garlic
isn’t fresh (“no Y”). Perfect match. We don’t even have
to read any other answer choices because we just
matched the entire stimulus point by point.

For the record:
(B) actually connects statements correctly. Connecting
the first two sentences, we learn that if the jar is held
over the burner for more than 2 minutes (“X”), it will
reach optimal temperature (“Y”), which will in turn
cause its contents to liquefy (“Z”). The conclusion of
(B) makes a sound deduction based on the connection
of these statements. In our algebraic notation, this
argument would have read as follows: “If X → Y; if Y →
Z; X occurred, so Z occurred.” This is correct
reasoning. Eliminate.

(C) Again, let’s do some algebraic substitution. We’ll
let “book set with wooden type” equal “X,” “book more
than 200 years old” equal “Y,” and “book classified as
special” equal “Z.” In that case, the argument reads:
“If Y → Z; if X → Y; no Z, so no X.” If we contrapose
the initial statements in this argument, we’ll see that it
uses correct reasoning also. Eliminate.

(D) Abstracting the terms of this argument gives us “If
X → no Y” (mower operating = “X” and engine flooded
= “Y”), then “If Z → Y” (foot pedal depressed = “Z”).
But the conclusion becomes “no Z, so X.” We can’t
contrapose any statement to find out what happens if
there’s “no Z,” so the logic is certainly flawed here. It
just isn’t flawed in the same way as that of the
stimulus. Eliminate.

(E) follows exactly the same logically sound structure
as (C), just in a slightly different order: “If X → Y; if Y
→ Z; no Z, so no X.” Eliminate.