Answer:
B
Explanation:
Lots of nutrients without a lot of calories
In the nervous system which works on various organs in the body that control blood pressure , heart rate , liver functions etc
Someones focuses on free will and using that will to control one's behavior.
The best answer i can find are Protozoa Ricketts
Although Ricketts are a disease, ever source i can find claims it's the answer.
there are a few rare cases of heartworm in humans, where it is usually found as a single worm in the lung versus heart.
there are rare cases since humans are not a natural host for heartworm, it is usually in animals but cannot be spread from animal to animal.
symptoms are trouble breathing, coughing, vomiting, weight loss, fatigue etc.
If you think you have heart worm from a pet, it is unlikely but if you match the symptoms you should see a doctor.