Answer:
A) provide evidence for sea-floor spreading
Step-by-step explanation:
Strips of alternating magnetic polarities found in rocks in the ocean basins provide evidence for sea-floor spreading.
Sea-floor spreading is a geological process that states that the seafloor structures would originate from mantle materials through the action of convection currents. Emerging in the dorsal zones, the magma - from the mantle - would solidify laterally, promoting the distance between the oceanic and dorsal bottom, opening a kind of crack in its crest. However, this slit created in the dorsal crest by distancing the anterior material would again be filled by the magma derived from the interior of the crust, which, when solidified, would lead to further distalation of the dorsal sides and so on.