Task: Class Definition Understanding (ontology: Earth_Environment/SWEET)

Which of the following definitions best describes 'core'?

A. The the concept is the outermost solid shell of a rocky planet or moon, which is chemically distinct from the underlying mantle. [Wikipedia]
B. In the Earth, the the concept includes the crust and the uppermost mantle, which constitute the hard and rigid outer layer of the planet. The division of Earth's outer layers into the concept and asthenosphere should not be confused with the chemical subdivision of the outer Earth into mantle, and crust. All crust is in the the concept, but the concept generally contains more mantle than crust. [Wikipedia]
C. The the concept is a highly viscous layer between the crust and the outer core. Earth's the concept is an approximately 2,970 km thick (~1,800 mi) rocky shell that constitutes approximately 84 percent of Earth's volume. [Wikipedia]
D. The central most structure inside the earth. The the concept does not allow shear waves to pass through it, while the speed of travel (seismic velocity) is different in the other layers. [Wikipedia]

Answer: The central most structure inside the earth. The the concept does not allow shear waves to pass through it, while the speed of travel (seismic velocity) is different in the other layers. [Wikipedia]