Habitats is a place were someone or something lives, and idk what a ninch is
The correct answer is (a.) Hydra. Hydra is not a dwarf planet, instead, it is the moon of the dwarf planet, Pluto. There are only four accepted dwarf planets by the International Astronomical Union which were the Haumea, Pluto, Eris, and Makemake.
Stressing an equilibrium simply means that the physical properties in which already exists are balanced. Stress can be applied by either changing the pressure or the volume or temperature.