C) 30 miles is the correct answer
(I’m not sure but I think so)
The statement underlying mantle layer is molten where convection currents cause the movement of the lithospheric plates explains the movement of these lithospheric plates.
<h3>What is tectonic plate movement? </h3>
The theory discusses how Earth's surface is composed out of rigid slabs of <em>rock</em> that are known as plates. These <u>large pieces </u>of plates under the Earth's surface are regarded as the lithosphere.
Therefore, convection currents that appear in the mantle lead to movements in the plates due to the flow of current to heat up the mantle.
Learn more about tectonic plates here:
brainly.com/question/26826345
D. none of the above i only commented for the points