Passage Summary: To save rhinos from extinction caused by poaching, we should just cut off their horns ourselves so poachers have no reason to kill them.

Conclusion: Periodically removing the horns of all rhinoceroses is an effective strategy for ensuring the species' survival.

Reasoning: Poachers are motivated by the illegal trade in horns; removing the horns eliminates the incentive for poachers to hunt the animals.

Analysis: This argument assumes that the solution (trimming horns) doesn't accidentally cause the very problem it's trying to solve (extinction). We must assume that rhinos can survive, reproduce, and defend themselves effectively without their horns. Additionally, the argument assumes that poachers won't kill hornless rhinos for other reasons, such as out of spite or to prevent themselves from wasting time tracking the same animal again. Look for an assumption that confirms the horn-trimming process itself is not fatal or that the absence of horns doesn't lead to a different cause of death.