Which of the Following Is the Best Definition of Homeostasis

Which of the following is the best definition of homeostasis?

A) The regulation of temperature, hydration, blood chemistry and other factors into order to keep these within a healthy range
B) The formation of vivid, stable memories by strengthening neural connections
C) The determination of sexual orientation by regulating hormones in the body
D) The tendency of the body to remain still, unless the environment provides strong motivation for movement