Homeostasis is the process of maintaining a constant _ environment despite_condition.

Explanation

Homeostasis refers to the body's ability to maintain a stable internal environment even when faced with external changes. In the context of the question, the correct answer is option B: 'internal, external'. This is because homeostasis involves regulating internal conditions (like temperature, pH, and water balance) to remain constant despite changes in the external environment. Option A is incorrect because it reverses the relationship between internal and external environments. Option C is incorrect because only one of the statements is true. Option D is incorrect as option B provides the correct understanding of homeostasis.