C is the correct anwser because it proves how we are very dependent on chemicals.
The overall specific gravity of the earth is much higher than the specific gravity of crustal rocks which means the earth is about twice as heavy as the rocks on the surface would suggest. Iron meteorites are thought to have the same composition as the average earth, and the meteorites contain a lot more iron than the Earth's surface rocks.
Vast flat areas does NOT describe the land of the Czech Republic.
Increase arable land for farming.
Hope this helps! :)
