- Fri Sep 12, 2025 11:53 am
#116171
Hi Halfie,
First, just to clarify, did you mean that you chose Answer D or E rather than Answer C? The reason that I ask is that Answer C does not have the word "some," but Answer D and E do have the word "some."
This argument concludes "that vitamin C has no real benefit in reducing the severity of acne." This conclusion is based on the fact that, among the subjects who did not know what pill they were given, no difference was found between these two groups. This argument assumes that there were no relevant differences between the two groups besides what pill they were given. In a properly conducted experiment, the two groups should be randomly assigned so that any other factors (genetics, diet, lifestyle, etc.) that could affect the outcomes are eliminated.
Answer A absolutely weakens the argument. If one of the groups (the Vitamin C group) has a history of suffering from more severe acne than the other group, it completely invalidates the study. Since the conclusion relies on the results of the study, invalidating the study weakens the argument.
I expect what may be giving you trouble is the specific wording in Answer A of "had a history." You may feel that this doesn't necessarily indicate that these people had more severe acne during the study. While that may be true for some of the subjects, it also may not be true. All else being equal, one would expect that people who have a history of suffering from more severe acne than another group will be (on average) more likely to suffer from severe acne at any given time (including during the study) than the other group. While the wording "had a history" is in the past tense, that does not mean that these patients are no longer more likely to suffer from severe acne. A person's medical history can/does impact their likelihood of having/getting present and future medical conditions.