Mineral deposits at divergent ocean plate boundaries primarily form through the process in which metals dissolve in superheated water, forming minerals when the water cools.
At divergent boundaries, tectonic plates move apart, allowing magma from the mantle to rise and create new oceanic crust. This process often includes hydrothermal vent systems, where seawater penetrates the ocean floor, gets heated by the underlying magma, and becomes enriched in dissolved metals. As this superheated, mineral-rich water is expelled into the colder ocean water, the minerals precipitate and crystallize, forming deposits around these hydrothermal vents.
The other options you mentioned pertain to different geological processes, but the key mechanism of mineral formation at divergent boundaries highlights the interaction of superheated water and cooling environments leading to mineral deposition.