What natural phenomenon occurs frequently in the Pacific Ring of Fire?

The correct choice is volcanic eruptions, which frequently occur in the Pacific Ring of Fire. This area is characterized by a high concentration of active volcanoes and tectonic activity due to the movement of several tectonic plates. The Pacific Ring of Fire is essentially a horseshoe-shaped zone encircling the Pacific Ocean, where subduction zones, ocean ridges, and transform faults are prevalent. As the oceanic plates subduct under continental plates, it leads to melting of the crust and the formation of magma, which can rise to the surface and result in volcanic eruptions.

Tornadoes primarily form in certain climatic conditions within land, particularly in regions like the central United States, rather than in the Pacific Ring of Fire. Earthquakes also are common in this region due to the tectonic activity, but the question specifically asks about natural phenomena that are related to volcanic activity. Hurricanes occur over warm ocean waters and are generally associated with tropical regions, which are not a defining characteristic of the Pacific Ring of Fire.