Why might the emission of radon gas be useful in predicting earthquakes?
a) Radon gas is released from fault zones when stress accumulates, providing a warning sign of impending earthquakes
b) Radon gas absorbs seismic waves, reducing their intensity and indicating the proximity of earthquakes
c) Radon gas causes changes in the Earth's magnetic field, which can be measured to predict earthquakes
d) Radon gas is a byproduct of volcanic activity, which often precedes earthquakes in volcanic regions
