Viruses responsible for causing polio and hydrophobia are
A. Neurotropic
B. Viscerotropic
C. Dermotropic
D. Pneumotropic

Hint: Polio (poliomyelitis) is a disabling and life-threatening disease caused by the poliovirus. The virus spreads from person to person and can infect a person's spinal cord (CNS), causing paralysis (can't move parts of the body).

Complete answer: Poliomyelitis (polio) is a highly infectious disease caused by three types of polioviruses. The poliovirus is a virus that destroys the central nervous system (CNS) and causes paralysis. There are three wild types of poliovirus; type 1, type 2 and type 3. People need to be protected against all three types in order to prevent the polio disease. The polio vaccination is the best protection against this disease. On the other hand, hydrophobia is caused by the rabies virus, which is a neurotropic virus. Hydrophobia refers to the fear of water or any liquid, which is the major symptom of the disease. With the onset of paralysis, it also affects the oropharyngeal muscles, swallowing and breathing centres in the brain. Hydrophobia causes neurological disorders, therefore, both viruses are neurotropic in nature.
a) Viscerotropic viruses (viscerotropic disease, VTD) is defined as acute multiple organ system dysfunctions that occur following vaccination. The severity of the viscerotropic disease ranges from relatively mild to severe multiple organ system failure and death.
Hence, the correct answer is option A.

Note: Dermotropic viruses attack the largest organ of the body, i.e. skin. Diseases caused by dermotropic viruses are cervical cancer, herpes simplex, shingles, warts, measles and chickenpox. Vicerotropic viruses affect the internal organs of the body, for example, the abdomen. Pneumotropic viruses cause common diseases. It is a common cold virus (several viruses include rhinovirus, coronavirus and adenovirus).