Hint: In order for you to arrive at the correct answer, try to guess the causative agent of the disease mentioned below. Most of the diseases that are caused to humans are due to the effect of bacteria. Viral infections are also common but more common are the bacterial infections.
Complete answer: Let us look at the causative agents and the corresponding symptoms of the diseases mentioned above. 1.Polio- It is generally caused due to the polio virus and is also known as the poliomyelitis. The virus associated spreads when infected fecal matter enters a healthy person thus infecting the person. Infection of the upper respiratory tract, nausea, vomiting , constipation and abdominal pain. It can be paralytic or non paralytic. 2. Pyorrhea- It is also known as the periodontal disease or the gum disease. It is an inflammatory disease of the gum and generally causes redness, swelling, pain and bleeding of the infected area. It generally arises due to poor hygiene that leads to the accumulation of bacteria at the gum line and also may occur due to underlying diseases such as diabetes. 3.AIDS- It is generally caused by the Human Immunodeficiency Virus(HIV).The infection begins when an infected person transmits the virus when: > He has unprotected intercourse. > Through mother to her child. > Through blood transfusions. > Through infected needles. Symptoms can be various but the most pronounced ones are rapid weight loss, recurrent fevers due to decreased immunity, extreme tiredness and continued swelling of the lymph glands among many other symptoms.
Hence, the correct option is B Pyorrhea.
Note: The Human Immunodeficiency virus is a retrovirus. This means that it inserts a part of its RNA into the DNA of the host cell thus changing its genome.By doing this,they hijack the machinery of the cell to make its own proteins that ultimately leads to the formation of new viruses.