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

The San Andreas Fault in California serves as a prime example of a transform boundary. This type of boundary occurs where two tectonic plates slide past one another horizontally. In the case of the San Andreas Fault, the Pacific Plate and the North American Plate are moving in opposite directions along this fault line.

Transform boundaries are characterized by a lack of volcanic activity, as opposed to divergent or convergent boundaries where plates move apart or collide, respectively. Instead, the movement can lead to significant seismic activity, such as earthquakes, due to the stress that builds up when the plates become locked together and then suddenly release. The San Andreas Fault is particularly well-known for its history of generating powerful earthquakes, making it a fitting example of this geologic feature.

By contrast, other options represent different types of boundaries. The Mid-Atlantic Ridge is a divergent boundary where new oceanic crust is formed, the Himalayan region is a convergent boundary resulting from the collision of the Indian and Eurasian plates, and the East African Rift is a divergent boundary where the African plate is splitting into two. Each of these features operates under distinct tectonic processes that do not align with the characteristics of transform boundaries.