Below was how approached the question - including the choice between the two options:

First tackled blanks (ii) and (iii) - do let me know if that is not clear.
Debates over free will have always focused on the extent to which humans may be said to be fully (i) _________ their actions.Dr. Wegner in his article deliberately and artfully eschewed the traditional talking points of the controversy, instead asking a tangential, though possibly more fundamental, question: What effect does a person’s belief in free will have on his or her well-being?

So what do we get from the context:
"Free will" is a controversial topic, and whenever this is discussed a particular point a always at the center of it. This is something which was cleverly omitted from one of the scholarly articles - probably knowing the controversial nature etc.

What is the result of "will" / "free will" ? => actions;
What could be good/bad/controversial ? => outcome/impact of these actions
Hence we are looking for a word that assigns some form of accountability for these actions/outcomes (which is the topic of controversy in the discussion of "free will")

When I look at the options:
"aware" - seems like a neutral word, it doesnt ring of accountability we are looking for, it lacks "strength" that we are looking enough to make a controversy.=> but I will keep it, unless I find a better word
"responsibility" - seems apt and has the characteristics we are looking for. (a much better choice than "aware")

"aware" would be my second best choice within the options.

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