The type of plate boundary where plates move apart, resulting in upwelling of material from the mantle to createnew seafloor, is referred to as a plate boundary

The type of plate boundary is divergent/constructive plate boundary.

Divergent plate boundary, also known as constructive plate boundary is where the plates move apart under the rising convection current of magma.

As plates move apart, cracks are formed and the upwelling magma from mantle would fill the cracks. Once the lava cools down, new plate material is created to create new seafloor. This is also called seafloor spreading.

Therefore, the answer is divergent/constructive plate boundary.

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divergent plate  boundary

answer; i believe the correct answer is (b) dutch van der linde