The observed effect the author is trying to explain? The rebound in the fish population at Quapaw Lake.
The author's proposed cause? The ban on fishing, i.e. less fishing.
This is a Weaken question, so we are looking for an answer choice that weakens this argument.
How do we weaken a Cause & Effect argument?
(1) Cause without Effect
(2) Effect without Cause
(3) Alternate Cause
(A) is completely irrelevant here. This argument is about the reason for the rebound in fish at Quapaw Lake. This argument is not about the reason for the continued decline of the fish population at Highwater Lake.
(B) is the correct answer because it effectively shows effect (i.e. rebound) without cause (i.e. less fishing). There was never a fishing issue at Quapaw Lake, so the fishing ban would not have impacted the amount of fishing taking place.
As such, (B) clearly weakens the argument and it is the correct answer.
Hope that helps! Please let us know if you have any other questions.
