Which of the following is an example of a long-term challenge? A. A medical diagnosis of multiple sclerosis
B. A severe bout with a seasonal flu or cold
C. Choosing which college to attend in the fall
D. Multiple high-stakes exams in the same week​

A and C are both long term challenges, I'm pretty sure it's A.

Explanation:

Personal experience, I have arthritis and it's a long term challenge.

love

medication

exercise

rest

fluid balance is an aspect of the homeostasis of organisms in which the amount of water in the organism needs to be controlled, via osmoregulation and behavior, such that the concentrations of electrolytes (salts in solution) in the various body fluids are kept within healthy ranges. the core principle of fluid balance is that the amount of water lost from the body must equal the amount of water taken in.