Under the leadership of Mikhail Gorbachev, the doctrine of Perestroika called for more local control and free-market practices. The correct option among all the options that are given in the question is the second option or option "B". I hope that this answer has come to your help.
Answer: Earthquake refers to the sudden shaking of the earth due to the release of energy by the seismic ways in the earth's interior. An earthquake of magnitude 2 is exactly ten times bigger, as well as about 31-33 times stronger than that of magnitude 1 .
Richter scale is used to measure magnitude of an earthquake, that means how much energy has been released due to the release of seismic waves.
Seafloor spreading<span> is a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. </span>Seafloor spreading<span> helps explain continental drift in the theory of plate tectonics. </span>
The metric unit for Mass is a gram