Answer:
b) When only urchins were removed, limpets increased in abundance and reduced seaweed cover.
Step-by-step explanation:
The accumulation of seaweed in aquatic bodies can kill the biodiversity of these environments. This problem occurs when there is an excessive proliferation of algae that, finding more food, reproduce ferociously, and end up polluting. And where there is pollution life can die. In this scenario, the hedgehogs and limpets can be very important, because by using seaweed as food, they reduce the problem of their excessive proliferation.
Much research has been done to evaluate the relevance of these two animals in combating pollution caused by the proliferation of seaweed. In the case of the research shown in the question above, seaweed cover increased much more when the sea urchins and limpets were removed than when only the sea urchins were removed. This probably happened because when only the hedgehogs were removed, the limpets increased in abundance and reduced the coverage of seaweed.