Rift valleys can form when fractures in Earth's crust widen. The valley walls slowly move apart at a rate of only a few millimeters a year. Which type of boundary would rift valleys form at?
A. Convergent
B. Divergent
C. Transform
D. Transform Fault

B. Divergent

Explanation:

Rift valleys are usually formed at divergent margins where fractures in the earth's crust widens.

The fracture widens due the pulling apart of the plates that are involved.

a compound is a molecule made of atoms from different elements.

a. by the combination of an unlimited number of elements