‘Mission Indradhanush’ launched by the Government of India pertains to

The correct answer is: immunisation of children and pregnant women.

Let us understand why this is the correct answer by breaking down the background and purpose of Mission Indradhanush in detail.

What is Mission Indradhanush?
Mission Indradhanush is a flagship health initiative launched by the Government of India on 25th December 2014 by the then Union Health Minister J. P. Nadda. The mission was designed under the Universal Immunisation Programme (UIP) to accelerate the immunisation coverage across India.

Why the name "Indradhanush"?
The name "Indradhanush" means rainbow in Hindi. The mission is named so because, just like a rainbow has seven colours, the programme originally covered vaccines against seven deadly diseases. These diseases are:
1. Diphtheria
2. Pertussis (Whooping Cough)
3. Tetanus
4. Polio
5. Tuberculosis (TB)
6. Measles
7. Hepatitis B
Over time, additional vaccines (such as those for Japanese Encephalitis and Rotavirus) were also included, expanding the rainbow further.

Who does it target?
The mission specifically targets children up to 2 years of age and pregnant women who have been left out of or have missed the regular immunisation rounds. The goal was to ensure that every unvaccinated or partially vaccinated child and pregnant woman in the country receives full immunisation.

What was the key objective?
India's routine immunisation coverage was increasing at a very slow pace — roughly 1% per year. Mission Indradhanush was launched to increase full immunisation coverage to at least 90% of all children in India by 2020, a significantly accelerated target compared to the existing pace.

Intensified Mission Indradhanush (IMI):
In 2017, the government launched Intensified Mission Indradhanush (IMI) to further boost coverage in high-risk districts and urban areas where immunisation gaps remained large, reinforcing the same core objective of protecting children and pregnant women.

Why the other options are incorrect:
- Construction of smart cities pertains to the Smart Cities Mission, a separate urban development initiative.
- India's search for Earth-like planets relates to space exploration programmes under ISRO, not this mission.
- New Educational Policy refers to the National Education Policy (NEP) 2020, which is a completely separate policy domain.
None of these have any connection to Mission Indradhanush.

Conclusion:
Mission Indradhanush is entirely a public health and immunisation initiative. Its sole focus is on vaccinating children (up to 2 years) and pregnant women against life-threatening, vaccine-preventable diseases, making "immunisation of children and pregnant women" the unambiguously correct answer.