How much more ground motion is produced by an earthquake of magnitude 7.0 than by an earthquake of magnitude 4.0?

Ten times as much for each magnitude increase; thus a magnitude 7 is 1000 times more displacement than magnitude 4. Most earthquakes happen at the edges of a tectonic plates. A break in earth's crust along which blocks of crust slide relative to one another is called earthquakes. 

the answer is the last option or letter d)