If a Human Body Has the Capacity to Regulate Its

If a human body has the capacity to regulate its processes and maintain homeostasis, why does the body sometimes get out of balance?

A) Disease, illness, or extreme circumstances can overwhelm the body's ability to regulate.
B) Usually, errors in genetic coding end up being the cause.
C) Drugs like Adderall or alcohol disrupt the control mechanisms.
D) Some people are just better at regulation than others.
E) This is an active area of research now because the answer is not known.