The Right Answer

This is an Author's Purpose, or Function, question as indicated by the phrase "primarily in order to." In questions such as these, we have to identify WHY the author does something. As such, the answer will not be clearly stated in the passage.

The good news is authors pretty much only mention something to support one of their points. So why would the author mention the "classical conception of free will"? To support one of their points. So the strategy is to look around that phrase and find out what point the author is trying to make.

Point the author is trying to make:

The author states, "But researchers actually found a SURPRISING temporal relation between subjective experience and objectively measured neural events."

The answer that most closely matches this "surprising" point is E, indicate the reason that the results of the neuroscientists' study were surprising.

The Wrong Answers

A: The author is not "arguing" anything here. The author doesn't have a clear opinion either way.
B: The author is not "suggesting" anything here. "Suggest" has two meanings: recommend and imply. The author is clearly not recommending anything. Likewise, the author is not implying anything either. He or she is quite clear with the information.
C: The author is not giving an "explanation," or reason, for the unexpected results.
D: The author is not "casting doubt," or discounting, any ideas in the passage.