Deep sea ocean ecosystems in the region of hydrothermal vents typically have much higher biomass with greater presence of larger eukaryotic organisms than other deep sea ecosystems. Which of the following is most responsible for this difference? A.) temperature differences B.) greater O2 content in regions around hydrothermal vents C.) pressure differences D.)much greater numbers of photosynthetic organisms E.) presence of substantial amounts of highly reduced inorganic compounds and methane