Answer the following question given this paragraph: 

Some volcanoes form over active hotspots . Scientists count about 50 hotspots on the Earth. Hotspots lie directly above a column of hot rock called a mantle plume . Mantle plumes continuously bring hot rock up from the mantle toward the crust ( Figure below ). The rock melts due to the release of pressure.


Q: What is the column of hot rock that continuously brings hot rock up from the mantle toward the crust?

 Choices:

- volcanic vent

- hotspot

- flue

- mantle plume

A:
mantle plume
