Theory led to the development of the theory of plate tectonics. a.continental driftb. thermodynamicc. seafloor spreading

The theory is A. continental drift.

The lithosphere which is the outermost layer of the planet is broken into pieces called tectonic plates. In this scientific theory called plate tectonics, seven large and greater number of small plates are broken and moved separately. This theory is based on the concept of continental drift.  

In the geologic time, continents shift their position from the earth's surface. Similar fossils found on different continent's shores prove us that the continental drift is nothing but truth.

r=rho l/a where a is the area, l is the length and rho is resistivity so the greater the area the lesser the resistance thats why the earth pin is thicker bcos current follow the shortest path, so less resistive .