A group of concerned citizens was worried that their local water supply might be contaminated with naturally occurring arsenic. They decided to purchase a home arsenic monitoring kit and tested well water in their local area. After analyzing the data (shown below), the citizens wrote a letter to the editor of a local newspaper arguing that their data proved that the water supply is contaminated. They demanded immediate government action to address the problem. The local water board again tested the wells using their official water testing instruments and found average concentrations of 8.1 +/- 0.2 micrograms per liter. Assume the water board's reported measurements are the accepted value. The maximum permitted level of arsenic in water supplies is 10 micro-grams per liter. 

src="https://sciemce.com/media/4/ppg__1020817191133__f1q511g1.jpg" alt="" style="vertical-align: 0.0px;" height="119" width="470" /> Which earth system interaction is illustrated in this passage?

A. Geosphere to atmosphere
B. Geosphere to hydrosphere
C. Hydrosphere to biosphere
D. Hydrosphere to atmosphere

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Answer: B

Environmental & Atmospheric Sciences