It seems you understand that Author A would agree with answer choice B. To explain it briefly, take a look at line 24: "Blameworthiness should thus be removed from the legal argot." The author concludes this based on the very limited capacity of free will. People have at most a small amount of control over their actions, so they should not be blamed.
Let's identify the author's stance in passage B. Author B seems to accept that free will is very limited, or at least he/she does not dispute this. However, the author believes that blame has a role in society, regardless of free will. See line 51: "My sense is that blaming performs some useful social function, even if it is in some way 'false'." This tells me that Author B would disagree with answer choice B, making it a point of contention between the two authors.
