What is a rift valley? a. where continental plates collide and form rifts of folded mountains in the crust b. where the ocean floor appears to be splitting and magma is rising from the mantle c. where a continental plate collides with an ocean plate to form a subduction zone d. where two ocean plates collide forming a subduction zone

(Rift valley) a large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.

Here is the definition of Rift Valley-a large elongated depression with steep walls formed by the downward displacement of a block of the earth's surface between nearly parallel faults or fault systems.

I hope this helps :-)