Researchers notice that volcanic rocks exhibit regular and predictable variations in their magnetic properties depending on their age. Which of the following statements about the variations would both scientists most likely agree with?
A. Electric currents, the liquid outer core cause variation in the magnetic properties of volcanic rock.
B. Solar wind levels at the time the rocks were created determine the magnetic properties of the rock.
C. The varying magnetic properties of the volcanic rocks are a result of the status of the Earth’s fluctuating magnetic field at the time the rocks cooled.
D. The Earth’s magnetic field shields it from solar wind, thereby altering the magnetic properties of volcanic rocks.