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

Which of the following definitions best describes 'upper mantle'?

A. The uppermost mantle plus overlying crust are relatively rigid and form the lithosphere, an irregular layer with a maximum thickness of perhaps 200 km. [Wikipedia]
B. The the concept refers to the mantle in the region between the asthenosphere and the outer core. The upper boundary is defined as the sharp increase in seismic wave velocities and density at a depth of 660 km. [Wikipedia]
C. The mantle is divided into sections based upon results from seismology. The the concept is the region from 33–410 km (20 to 254 miles). The upper part of the mantle is composed mostly of peridotite, a rock denser than rocks common in the overlying crust. [Wikipedia]
D. The solid the concept was discovered in 1936 by Inge Lehmann and is generally believed to be composed primarily of iron and some nickel.[Wikipedia]

Answer: The mantle is divided into sections based upon results from seismology. The the concept is the region from 33–410 km (20 to 254 miles). The upper part of the mantle is composed mostly of peridotite, a rock denser than rocks common in the overlying crust. [Wikipedia]