Which of the following is an example of a divergent boundary?

A divergent boundary occurs when two tectonic plates move away from each other, often resulting in the creation of new crust as magma rises to fill the gap. The Mid-Atlantic Ridge is a prime example of this type of boundary, as it is a mid-ocean ridge where the Eurasian Plate and the North American Plate are pulling apart, allowing magma to emerge and form new oceanic crust.

This process leads to the formation of underwater mountains and contributes to seafloor spreading. The geological activity associated with divergent boundaries can also create rift valleys and significant volcanic activity as magma flows easily to the surface. This explains why the Mid-Atlantic Ridge is recognized as a key feature in plate tectonics studies regarding divergent boundaries.

In contrast, the other options represent different types of plate interactions: the San Andreas Fault is a transform boundary where plates slide past each other; the Himalayan Mountains were formed by the collision of two continental plates; and the Mariana Trench is a result of a convergent boundary where one plate is subducting beneath another. Each of these examples illustrates distinct tectonic processes different from divergence.