Option D. The mechanical layer of Earth that has the most active convection currents is Asthenosphere.
<h3>What is Asthenosphere?</h3>
The asthenosphere is the mechanically weak and ductile region of the upper mantle of Earth.
The asthenosphere, zone of Earth's mantle lying beneath the lithosphere and believed to be much hotter and more fluid than the lithosphere. It is the most active layer for convection current.
Thus, the mechanical layer of Earth that has the most active convection
currents is Asthenosphere.
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