Analyzing the Sentence and Blanks
The sentence describes how thought experiments are used in philosophy.

Major philosophical (i) ________ about morality, identity and rationality, for example, can often be (ii) ________ by thought experiments: short and simple expositions that pose an abstract and complex problem in a concrete manner with all the (iii)
________ factors removed.
- Blank (i): The word must describe what philosophers hold "about morality, identity and rationality." These are complex, fundamental areas of philosophy, and the context suggests something that needs to be clarified or solved.
- A. certitudes: Certainties/firm beliefs. If they were certainties, they wouldn't need to be solved or clarified. (Less likely)
- B. dilemmas: Problems, situations requiring a difficult choice, or a complex and difficult problem. This fits the idea that these are complex issues to be analyzed. (Strong candidate)
- C. dogmas: Authoritative, established principles or tenets. These are usually things accepted without question, not things that need to be "illuminated" or solved. (Less likely)

Choice for (i): B. dilemmas

- Blank (ii): The word must describe what happens to these philosophical dilemmas when they are addressed by thought experiments. Thought experiments are meant to clarify or solve the problem.
- D. mimicked: Imitated or copied. Thought experiments don't imitate dilemmas; they are used to analyze them. (Incorrect)
- E. illuminated: Made clear; explained or clarified. Thought experiments are effective because they make abstract, complex problems clear. (Strong candidate)
- F. evoked: Brought to mind. While thought experiments might bring dilemmas to mind, "illuminated" better captures the purpose of solving or clarifying. (Weaker than E)

Choice for (ii): E. illuminated
- Blank (iii): The word must describe the type of factors that are removed from the problem when it is presented in a concrete manner in a thought experiment. Thought experiments simplify problems by getting rid of unnecessary details.
- G. extraneous: Irrelevant or unrelated to the subject being dealt with; not essential. This fits the idea of removing non-essential details to focus on the core problem. (Strong candidate)
- H. inherent: Existing in something as a permanent, essential, or characteristic attribute. If inherent factors were removed, the problem itself would be destroyed. (Incorrect)
- I. pivotal: Crucial importance. These are essential factors; they would not be removed. (Incorrect)

Choice for (iii): G. extraneous


Final Sentence
Major philosophical dilemmas about morality, identity and rationality, for example, can often be illuminated by thought experiments: short and simple expositions that pose an abstract and complex problem in a concrete manner with all the extraneous factors removed.