Final answer:
According to the mantle plume model, hot spots are caused by mantle plumes.
Step-by-step explanation:
According to the mantle plume model for the origin of hot spots, the formation of hot spots is caused by mantle plumes. A mantle plume is a region of increased temperature that can cause melting of the lithospheric region. These mantle plumes are thought to be generated at the core-mantle boundary and can lead to the formation of hotspot-generated volcanoes.