What formed the Great Rift Valley?


1:volcanic activity and tectonic movement

2:a massive earthquake 200 years ago

3:a mountain range west of the valley

4:a massive basin in the valley's center

Verified Answer :

 The Great Rift Valley was formed by huge subterranean forces that tore the earth's crust apart, causing chunks of the crust to sink into the earth.

Therefore, #1. Volcanic activity and tectonic movement. 

  1. Volcanic activity and tectonic movement