Which scientist studies the earth's core, the mantle, the crust, continents, and the ocean floor?
a geologist
a meteorologist
an oceanographer
an astronomer

A. geologist

a geologist investigates about all the constituent materials of earth, the forces that act upon it and the earthly processes such as volcanic eruptions, landslides, floods, etc that have occurred in the past. its major focus is the changes associated with earth over time.