Read the scenario. A biologist is studying golden frogs that live in cool streams running through the rain forests of Central America. The biologist conducts a survey of the population and counts over 100 frogs in one mile of stream. The biologist returns to the same location one year later and counts only 20 frogs in that same stretch of stream. The biologist wonders why there are suddenly so few golden frogs. The biologist also observes that a mining company has set up a copper mine only a few miles from the stream. By reading studies on copper mining operations in other parts of the world, the biologist learns that the wastewater runoff from the mines is highly acidic and contains potentially toxic compounds. Which question most closely relates to the biologist's observations and collected data?