The correct answer is (c) 1981-91.
The decadal growth rate of population in U.P. was the highest during 1981-91. The population of U.P. increased from 110.86 million in 1981 to 140.86 million in 1991, a growth rate of 27.03%. This was the highest decadal growth rate of population in U.P. since 1901-11.
There are a number of factors that contributed to the high growth rate of population in U.P. during 1981-91. These include:
- A decline in the death rate, due to improvements in health care and sanitation.
- A rise in the birth rate, due to factors such as early marriage and a preference for large families.
- A net in-migration of people from other states.
The high growth rate of population in U.P. has had a number of negative consequences, including:
- Increased pressure on natural resources, such as land and water.
- Increased pollution and environmental degradation.
- Increased demand for basic services, such as education and healthcare.
- Increased social and economic inequality.
The government of U.P. has taken a number of measures to address the challenges posed by the high growth rate of population, including:
- Promoting family planning and contraception.
- Investing in education and healthcare.
- Providing employment opportunities.
- Developing infrastructure.
However, these measures have not been enough to significantly reduce the growth rate of population in U.P.