The asthenosphere is a part of which layer of Earth's interior?

Correct option is B

The asthenosphere is a part of the upper mantle. It lies below the lithosphere, extending approximately from 80 km to 200 km beneath Earth's surface. The asthenosphere is partially molten and behaves plastically, allowing the lithospheric plates to move over it. This layer plays a critical role in tectonic activities, including plate tectonics, volcanic activity, and earthquakes.
Information Booster:
· The asthenosphere is located between the lithosphere (above) and the lower mantle (below).
· It is composed of solid rock but behaves like a viscous fluid over geological time scales.
· The movement of tectonic plates occurs due to the flow within the asthenosphere.
· It acts as a lubricant for plate motions, which contributes to the dynamic nature of Earth’s surface.
· Temperature and pressure conditions in this layer allow partial melting, giving it its semi-fluid characteristics.
Additional Knowledge:
· The crust: The outermost layer of Earth, composed of continental and oceanic crust. It is rigid and brittle, not part of the asthenosphere.
· The outer core: Composed of liquid iron and nickel, it generates Earth's magnetic field but is unrelated to the asthenosphere.
· The inner core: Solid due to immense pressure, primarily made of iron and nickel, and has no role in tectonic plate movements.