Question

with the discovery of magnetic reversals, there was evidence that
the seafloor could create new continental crust
the seafloor contains alternate bands of minerals
only seafloor (oceanic) crust was capable of drifting
the seafloor contained a mechanism for plate tectonics

Explanation:

Magnetic reversals show alternating magnetic polarity in oceanic crust. This pattern supports seafloor spreading, a key mechanism in plate tectonics. New oceanic crust forms at mid - ocean ridges. As it spreads, it records Earth's magnetic field reversals. This provides evidence for plate movement.

• The seafloor doesn't create new continental crust directly. Continental crust forms differently.
• Alternate bands of minerals aren't the main significance. The magnetic pattern relates to plate movement.
• Both oceanic and continental plates can move (drift).

Answer:

the seafloor contained a mechanism for plate tectonics