Fact 1: Faulting of rock in Earth 's crust causes earthquakes. Fact 2: Fault zones are plates in the earth that slide and collide. Given the two facts above, plates in the earth do what which causes earthquakes?

Choose from:
1). Movement;
2). waves;
3). heat;
4). collide;
5). moves;
6). erosion;
7). break off;
8). friction;
Answer:
4).