The correct answer is: A. 7th April, 2015.
Mission Indradhanush is a national immunization program launched by the Government of India in 2015. The program aims to provide all children under the age of five with full immunization against seven vaccine-preventable diseases: diphtheria, pertussis, tetanus, poliomyelitis, measles, mumps, and rubella.
The program was launched on 7th April, 2015, by the Prime Minister of India, Narendra Modi. The program was launched in a phased manner, with the first phase covering 200 districts in 2015-16. The second phase covered 200 more districts in 2016-17, and the third phase covered the remaining districts in 2017-18.
The program has been successful in increasing the immunization coverage in India. In 2014, the immunization coverage in India was 62%. By 2018, the immunization coverage had increased to 90%.
The program has also been successful in reducing the number of deaths due to vaccine-preventable diseases. In 2014, there were 1.2 million deaths due to vaccine-preventable diseases in India. By 2018, the number of deaths had reduced to 0.6 million.
Mission Indradhanush is a successful program that has helped to improve the health of children in India. The program has increased the immunization coverage and reduced the number of deaths due to vaccine-preventable diseases.
The other options are incorrect because they are not the dates on which Mission Indradhanush was launched.