(A) vs. (C)

@Julie, Let's look at the structure of the argument. A thesis is presented that argues that motion is absolute A well-respected physicist claims that the thesis is incoherent. Since a thesis is incoherent, the motion cannot be absolute. Let's look at (A) & (C) (A) is wrong because the philosopher is not using technical terminology to reach his conclusion, all the terminology is only used in the context of describing the thesis; (C) is correct because the philosopher takes the physicist's claim as true and uses it as evidence to support his premise that "a thesis..is incoherent." Does that make sense? Let me know if you have any further questions.