The answer is a. A convergent boundary is where plates come together and a divergent boundary is where they move apart from each other.
Convergent and divergent boundaries, together with transform boundaries, are types of plate tectonic boundaries. The convergent boundaries are where tectonic plates come together. This results in the formation of mountains and subduction zones. The opposite of this is the divergent boundary. The divergent boundaries are where tectonic plates move apart from each other. At the divergent boundaries, oceanic crust is created.
