The correct answer is (a) Fungus.
Mucormycosis is a rare but serious fungal infection that can affect the sinuses, lungs, brain, and other organs. It is most common in people with weakened immune systems, such as those with diabetes, cancer, or organ transplants.
The fungus that causes mucormycosis is found in soil and decaying organic matter. It can enter the body through the nose, mouth, or skin. Once inside the body, the fungus can spread quickly and cause serious damage.
There is no vaccine or cure for mucormycosis. Treatment usually involves antifungal medications and surgery to remove infected tissue.
The other options are incorrect because they are not the cause of mucormycosis.
(b) Bacteria are single-celled organisms that can cause a variety of diseases, including pneumonia, meningitis, and urinary tract infections.
(c) Viruses are even smaller than bacteria and can cause a variety of diseases, including the common cold, the flu, and HIV/AIDS.
(d) Protozoa are single-celled organisms that can cause a variety of diseases, including malaria, sleeping sickness, and giardiasis.