Concept:The Mohorovičić (Moho) discontinuity is a seismic boundary inside the Earth that marks a change in rock composition and density.
Explanation:The Moho is the boundary that separates the Earth's crust from the mantle.
It was discovered by Croatian seismologist Andrija Mohorovičić in 1909.
At this boundary, seismic wave velocities suddenly increase because the mantle is denser and composed of different silicate minerals than the crust.
The depth of the Moho varies: it lies about
7–
8 km beneath ocean floors and about
35 km beneath continents.
This change in seismic speed clearly distinguishes the crust above from the mantle below.
Therefore, among the given options, the Moho discontinuity separates Earth's crust and the mantle, not the lithosphere and asthenosphere or other layers.
Answer:D. Earth's crust and the mantle