This has to be more specific..........but the name of the cell is called a galvanic cell and cations react at the cathode. Hope this helps.
I believe that option C should be correct
Answer:
<h2>Scientists use a wide variety of techniques to monitor volcanoes, including seismographic detection of the earthquakes and tremor that almost always precede eruptions, precise measurements of ground deformation that often accompanies the rise of magma, changes in volcanic gas emissions, and changes in gravity.</h2>