The conclusion of this argument is the last sentence, i.e. "This modest investigation thus supports the claim that one's astrological birth sign influences one's personality." How do we know this? Well investigators found 20 volunteers born under the sign of Gemini who were willing to be interviewed on a television program and to take a personality test.
Right away you should notice that this is a flawed argument. The author is basing his conclusion on a sample that we have reason to believe in unrepresentative because these 20 people agreed to be interviewed on a television program. Someone who is not social and extroverted would obviously not agree to be interviewed on a television program in the first place.
So let's take a look at answer choices (D) and (E):
Answer choice (D) is not a flaw in the method used by the investigators. The issue is not whether Geminis are representative of the population in general, but rather whether one's astrological birth sign actually influences one's personality. The investigators wanted to see if Geminis exhibited certain personality traits so they went out and found Geminis to test this hypothesis. The number of Geminis in this world is completely irrelevant.
Answer choice (E), on the other hand, points out the exact problem we identified above. This sample is not representative because by requiring people to be interviewed on a television program, the sample would naturally contain people who are social and extroverted.
Hope this helps! Please let us know if you have any other questions.
