Passage Summary: Lichens are unique organisms that soak up everything from the air and rain but can't get rid of the toxins they absorb, which can end up hurting them.

Reasoning: Lichens consist of fungi and photosynthetic organisms that absorb minerals from their surroundings but lack the ability to excrete them, making them sensitive to pollution.

Analysis: Since the stimulus is a set of facts, we must find a statement that is a logical consequence of those facts. The key detail is that lichens absorb substances but cannot excrete them, meaning whatever they take in stays in their system. You should look for an answer that suggests lichens can be used to measure environmental quality or that their internal mineral levels reflect the pollution levels of their habitat.