Question

select the correct answer.
how does the theory of plate tectonics support the theory of seafloor spreading?
a. when a tectonic plate meets the ocean floor, it submerges beneath it, increasing the total seafloor.
b. when two tectonic plates move toward each other, they converge to create a new ocean.
c. when a tectonic plate moves parallel to another plate, it creates a gap between the plates, which is filled by the ocean.
d. when two tectonic plates move in opposite directions, it causes magma to rise, creating a new seafloor.

Explanation:

To solve this, we analyze each option based on plate tectonics and seafloor spreading:

• Option A: Subduction (one plate submerging) reduces seafloor, not increase. Eliminate.
• Option B: Convergent plates (moving toward) form mountains/trenches, not new oceans. Eliminate.
• Option C: Parallel movement (transform boundaries) creates faults, not ocean - filled gaps. Eliminate.
• Option D: Divergent plates (moving opposite) allow magma to rise, solidify, and create new seafloor—this matches how plate tectonics supports seafloor spreading.

Answer:

D. When two tectonic plates move in opposite directions, it causes magma to rise, creating a new seafloor.