 
<translate> Iji zaa ajụjụ ahụ, tụlee ihe ndị na-esonụ: A na-enwe ndagwurugwu na-agba agba n'ókè nke efere dị iche iche, nke na-agbasa n'elu ala, nke na-agbasasịkwa n'elu ala, bụ́ nke ike ndị na-eme ka ala na-akpọnwụ na-emezi ka ọ dịkwuo omimi. Ya mere, azịza ya bụ oke efere dị iche. <eng> To answer the question, consider the following: A rift valley is formed on a divergent plate boundary, a crustal extension, a spreading apart of the surface, which is subsequently further deepened by the forces of erosion. So, the answer is a divergent plate boundary. 