Answer:
Homeostasis.
Step-by-step explanation:
Homeostasis may be defined as the ability to maintain the constant body temperature. The maintenance of homeostasis is an important characteristics of the living organisms.
As Aisha runs, she has lost her body water in form of the sweat. This causes water loss due to which she feels thirsty. After drinking water the water of the body is maintained properly. Her body's tells her that she need more water to maintain the homeostasis of the body in the form of thirst.
Thus, the answer is homeostasis.