The correct answer is - divergent.
A divergent plate boundary is plate boundary that is form by the sepration of the two distinct tectonic plates away from one another and result in the forming the ranges known as oceanic spreading ridges.
This type of plate boundary occurs due to the earthquack or volcanic erruption of from the mantle to surface of the earth. This magma or rises and forms oceanic crust by the solidifying of the moleten rocks.
Happy to help