The appropriate answer is doing. decreased atmospheric water vapor leads to an increased greenhouse effect. This is not true because water vapor is a green house gas and increasing the levels of it in the atmosphere will lead to more warming. All the other answers represent appropriate feedback mechanisms associated with global warming.
Echinoderms, they are among the most common invertebrate animals in the marine environment of virtually any part of the world, among them we can find species such as sea cucumber , salmon and cod fish, they have chamois cloth like outer layer, then we have the Crinoids, another example of marine species with feather, popularly they are called sea lilies and feathery stars, they have a solid calcite skeleton; they were so abundant in the paleozoic seas that their remains formed large limestone thicknesses.
Organ system is the answer