The correct answer is: b) 10 years.
The Census of India is a decennial census of India, conducted by the Office of the Registrar General and Census Commissioner, India, under the Ministry of Home Affairs. The census is the largest peacetime operation in India, and is used to collect data on the population, households, and economic activity in India.
The first census of India was conducted in 1872, and has been conducted every 10 years since then, except for the years during World War I and World War II. The most recent census was conducted in 2011.
The census data is used to plan for the development of India, and to monitor the progress of development. It is also used to allocate resources to different parts of the country, and to determine the number of seats in the Lok Sabha and the Rajya Sabha.
The census data is also used by researchers to study the population of India, and to track changes in the population over time. The data is also used by businesses to make decisions about where to locate their businesses, and to target their marketing campaigns.
The census data is a valuable resource for the government, businesses, and researchers. It is used to make decisions that affect the lives of millions of people in India.
The other options are incorrect because:
- Option a) is incorrect because the census is conducted every 10 years, not every 5 years.
- Option c) is incorrect because the census is conducted every 10 years, not every 15 years.
- Option d) is incorrect because the census is conducted every 10 years, not every 20 years.