Answer:
Immune
Step-by-step explanation:
The immune system helps to protect our body from all sort of organisms ranging from invading toxins and micro-organisms which negatively affects an individual’s health and well being.
Stress has an adverse effect on the immune system such that it weakens and suppresses the functions of the required antibodies in the body system. This is the reason why many aged people fall sick because they have gone through more stress when compared to younger people.