Passage Summary: There aren't enough panthers to keep the species alive forever, and there is no more room in their current home for the population to grow.

Reasoning: The Florida panther population is currently between 70 and 100, but it requires 250 members to be self-sustaining; meanwhile, their current habitat is already at its maximum capacity.

Analysis: In a 'Must be True' scenario, we are looking for a mathematical or logical certainty derived from the provided constraints. We are told the population needs to hit 250 to survive, but the current land can't support more than the 100 already there. Therefore, it is a logical necessity that the population cannot become self-sustaining unless something changes regarding their habitat. Any valid inference will likely focus on the fact that the current environment is a hard ceiling preventing the species from reaching its survival threshold.