The correct answer is - C. the San Andreas Fault.
There's multiple types of boundaries between the tectonic plates, convergent boundary, divergent boundary, and transform boundary. In the present, there's few geographic examples of transform boundaries around the globe, one of which is located along side the western coast of the United States, and is manifested with the well known San Andreas Fault in the state of California.
The transform boundaries are boundaries formed when two or more tectonic plates are sliding against each other. From the pressure they create to each other, it is very common that lots of cracks, parallel to the boundary, are forming in the area. In California, the biggest and best known crack of this type is the San Andreas Fault.
