Explanation:

Polio is a crippling and potentially deadly viral infectious disease that affects the nervous system.

• The virus is transmitted by person-to-person mainly through the faecal-oral route or, less frequently, by a common vehicle (for example, through contaminated water or food).
• It largely affects children under 5 years of age.
• India received polio-free certification by the WHO in 2014, after three years of zero cases.
• The last case due to wild poliovirus in the country was detected on 13th January 2011.
• Every year, 24th October is observed as World Polio Day in order to call on countries to stay vigilant in their fight against the disease.
• It was established to commemorate the birth of Jonas Salk, who developed an Inactivated (killed) Polio Vaccine (IPV).

Hence only statements 2&3 are correct.