Explanation

First, the stimulus takes the statement “All intelligent people are nearsighted” (“All X are Y” or “If X, then Y”) and tries to conclude something based on the consequent—i.e., on the Y term. So the first mistake the stimulus makes is to argue along the lines “All intelligent people are nearsighted; I am nearsighted, therefore I must be intelligent.” But the stimulus doesn’t stop there: it intensifies both terms, arguing that since I am very nearsighted, I must be very intelligent (a genius, in fact). There’s no grounds for connecting degree of nearsightedness to degree of intelligence, so that’s a second flaw. (D) shows the same pattern. Based on the statement “All tall people are happy” or “All X are Y,” (D) infers not simply that “Since John is happy, he must be tall” (or “Y, therefore X”) but goes the extra mile and concludes “Since John is extremely happy, he must be extremely tall.”

(A) takes the evidence, “All intelligent people are nearsighted” (All X are Y), and goes on to infer something from the negation of the consequent or the Y term: “I have perfect vision” (i.e. “I am NOT nearsighted” or NOT-Y), therefore I must be stupid” (i.e. “I am NOT intelligent” or NOT-X). Thus, although (A) does include the same intensification we find in the stimulus, the structure of the argument is different.

(B) follows the stimulus in reasoning “All X are Y; Y, therefore X” but misses the second flaw, that of intensifying the terms.

(C) is a mess; there’s nothing connecting the idea of the number of legs an animal has to its size, nothing relating pigs to spiders, and, in fact, nothing remotely similar to the stimulus.

(E) simply runs “All X are Y (All geniuses are very nearsighted); X (I am a genius), therefore Y (I must be very nearsighted). That’s valid and not parallel.

Answer: D