Answer:
The correct answer would be - extracellular fluid.
Explanation:
Changes in extracellular fluid helps the homeostatic mechanism to monitor and regulate the composition of the body fluids. This process involves regulatory hormones such as anti diuretic and aldosterone in order to maintain body fluids.
It is easy to regulation of the extracellular fluid than trying to regulate 100 trillion cells present in Intracellular fluids as ICF have 10% more water in comparison of ECF.
Thus, the correct answer is : extracellular fluid.
