The correct answer is: B. Bacteria
Anthrax is a serious infectious disease caused by the bacterium Bacillus anthracis. It affects both humans and animals. Anthrax can be found naturally in soil and water, and it can be spread to humans and animals through contact with infected animals or contaminated animal products.
There are three main forms of anthrax: cutaneous, inhalational, and gastrointestinal. Cutaneous anthrax is the most common form, and it is characterized by a black lesion on the skin. Inhalational anthrax is the most serious form, and it can be fatal if not treated. Gastrointestinal anthrax is the least common form, and it is characterized by nausea, vomiting, and diarrhea.
There is no vaccine for anthrax, but there are antibiotics that can be used to treat it. Anthrax is a reportable disease, which means that doctors are required to report all cases to the government.
Viruses are acellular, meaning they do not have a cell nucleus. They are much smaller than bacteria, and they can only replicate inside living cells. Viruses are the cause of many diseases, including the common cold, the flu, and AIDS.
Bacteria are single-celled organisms that are much larger than viruses. They have a cell nucleus, and they can replicate on their own. Bacteria are the cause of many diseases, including pneumonia, strep throat, and tuberculosis.
Protozoa are single-celled organisms that are larger than bacteria. They have a nucleus, and they can replicate on their own. Protozoa are the cause of many diseases, including malaria, giardiasis, and toxoplasmosis.
Helminthes are multicellular organisms that are larger than protozoa. They are not single-celled, and they do not have a nucleus. Helminthes are the cause of many diseases, including tapeworm infection, roundworm infection, and hookworm infection.