Question

over the last 250 million years, the world changed from a single land - mass to a number of different continents. one reason for the change is expanding ocean floors. what causes ocean floors to expand? a. convergent plates b. divergent plates c. slab pull d. split

Explanation:

Divergent plate boundaries are where new ocean - floor crust is formed as tectonic plates move apart. Magma rises up to fill the gap, creating new crust and causing the ocean floor to expand. Convergent plates collide, sub - pull is not a term related to ocean - floor expansion, and split is too general.

Answer:

B. Divergent plates