Adivergent boundary at two continental plates can result in a

continental volcanic arc
subduction zone
volcanic island arc
rift valley

The correct answer is - rift valley.

The divergent plate boundaries are occurring when two plates are moving away from each other. If that is happening in the ocean, than an ocean ridge is formed, while on the land a rift valley is formed.

This can be seen in the eastern part of Africa, where there's rift valleys all across this part of the continent that is moving away from the African mainland. As the rift valleys become bigger and bigger, over time they tend to fill in with water from the ocean, thus separating them from the part that they are moving away from.

the answer is b antarctica