Answer:
c) the amount of energy released at the focus
Explanation:
Mercalli scale:
Mercalli scale is used to measured the intensity of earthquake.By observing the of earthquake it give the information about the intensity of earthquake.Mercalli scale is a linear scale.
As we know that Richter scale is also used to described the earthquake by measuring seismic wave which generated by earthquake.
So we can say that Mercalli scale of earthquake intensity is based on the amount of energy released at the focus.
So option C is correct.
c) the amount of energy released at the focus