Why is the age of the ocean crust used as evidence for plate tectonics?

The great age of continental rocks results from their inability to be subducted. ... We also know that the increase in age of ocean crust away from ocean basins results from creation of new sea floor at the MORs, with destruction of older sea floor at ocean trenches, which are often located near continental margins.

Explanation:

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

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