The state of maintaining a stable internal environment regardless of changing external conditions is called

The state of maintaining a stable internal environment regardless of changing external conditions is called homeostasis.

Homeostasis.

Explanation:

Homeostasis may be defined as the characteristics of living organisms to maintain the stable internal environment of an organisms. The external environment should not effect the internal body environment.

Humans have developed various internal mechanism to maintain their steady internal environment. They have receptors on their surface to detect the changes in the external and internal environment.

Thus, the answer is homeostasis.

b would be the right answer