What midwestern weather conditions combine to form the huge thunderstorms that can spawn tornadoes

Heavy clouds hang low over a dilapidated homestead in the Midwest, foretelling a possible tornado. Tornadoes form when the updrafts that supply storms with warm, humid air become a vortex, or high-speed whirlwind.

Explanation:

c. seafloor spreading occurs.

d. crust becomes molten rock.

e. denser plates slide under lighter plates.