The correct answer is upwelling from equatorial to Polar Regions results in bringing oxygen from the epipelagic zone to deeper oceanic zones.
It is a process in which the wind mediated motion of nutrient-rich, dense, and cooler water is moved towards the surface substituting the nutrient depleted and warmer surface water. The epipelagic zone refers to the upper layer of the ocean, which is abundant in oxygen and gets the majority of the sunlight for the procedure of photosynthesis. The upwelling of water from the equatorial to the polar region brings oxygen.