Questions 1 and 2 are based on this passage

At first glance, the nineteenth-century Atlantic halibut fishery fit the typical pattern of fisheries collapse. It followed predictable boom-and-bust cycles of commercial potential, enthusiastic fishing, resource strain, declining productivity and ultimately, collapse. Yet, unlike many other species, halibut was long disdained by fishers and consumers despite its abundance. Lack of commercial value did not entirely protect halibut, since fishers frequently caught halibut along with their target fish, cod, though they discarded halibut as worthless. Between 1840 and 1880, however, consumer demand shifted, elevating halibut to a desirable commodity. The threat to halibut stocks was compounded because fish dealers imposed a selection process based on grading the catch, a system that encouraged fishers to jettison all but the highest-graded, most valuable among the fish they caught.

In the context of the passage, the highlighted sentence serves primarily to

rule out a possible explanation for the timing of a particular historical event

identify a historical circumstance that disrupted an otherwise common cycle

provide a clue that might help to explain an unexpected outcome

suggest that a pattern that has widely been considered typical is actually somewhat unusual

identify what triggered a chain of events that has come to seem predictable

Select one answer choice.