At which location does gravity play a role in moving tectonic plates? at the edge of the plates. in the core. in the mantle. in the middle of a continent

B. At the edge of the plates

Explanation:

Gravity is the principal driving force of plate tectonics (second one is convection). It causes different density plates to move on the Earth's surface. However, when a denser plate coincides the less denser plate, the high density plate subducts below the lesser density plate. The process, therefore, is called subduction. During this collision of plates, shearing resistance increases and all pressures come at the edge of the plate. The process continues and the lithosphere drags the rest of the plate. The portion of plate below the less denser plate then reaches the mantle. Here, the edge of plate is destroyed due to high temperature of mantle as well as pressure.

c. earths continental crust is thicker than its lithosphere.

because, the lithosphere is the outermost layer of the earth/ 100 km thick and is defined by its machanical properties.the lithosphere contains oceanic and continental crust that varies in age and thickness across locations and geologic time. the lithosphere is the coolest layer of the earth in terms of temperature. the term lithosphere should not be confused with the use of "geosphere" which is used to indicate all of earth systems, including the atmosphere, hydrosphere   and biosphere. the surface of the earth can be divided into the continental crust and the oceanic crust.   the continental crust is made mostly of granite while the oceanic crust is made of basalt. the average thickness of the continental crust is 25 miles and the average thickness of the oceanic crust is 5 miles.   three types of rock, igneous, sedimentary, and metamorphic, make up the surface of the earth. that's why 3 option is preferable.