The correct answer would be carcinogens. Carcinogens can disrupt cellular homeostasis and can even lead to uncontrolled cell division and form of cancers. These are substances that damages the cellular metabolic processes in the body. Carcinogens are found everywhere; it may be in our food, radiation or even some of the ingredients of the things we use daily.
The answer is option B "psychiatrist." Psychiatrist are specialized in medicine and on finding cures for common diseases which would make them doctors. Also its not option A because a <span> psychologist is a person who studies in behaviors which is a therapist, its not option C because a social worker works mainly in families but not for the health. Its also not option D because a case manager who is placed to render court cases.
Hope this helps!</span>