Correct Option (D)
The rate of population growth is increasing due to faster decline in death rate than in birth rate.
This conclusion is directly supported by the provided statements. Statement 1 indicates that the overall rate of population growth is increasing. Statement 2 specifies that the death rate is declining faster than the birth rate. When the death rate decreases at a more rapid pace than the birth rate, and assuming the birth rate remains higher than the death rate, the natural increase in population (births minus deaths) will expand. This expansion directly contributes to an accelerating rate of population growth.
Incorrect Options:
Option A: The rate of population growth is increasing due to rural-urban migration.
- Statement 4 confirms rural-urban migration. However, rural-urban migration represents an internal redistribution of the existing population within a country. While it impacts the demographic composition of specific regions (urban vs. rural), it does not inherently cause an increase in the overall national population growth rate. The overall growth rate is primarily determined by birth rates, death rates, and international migration.
Option B: The rate of population growth is increasing due to decline in death rate only.
- While a decline in the death rate is a significant factor contributing to population growth, the word "only" makes this option an incomplete explanation in the context of the given statements. Statement 2 provides a more precise relationship: the death rate is declining faster than the birth rate. This relative decline is the key driver for the increase in the growth rate, rather than just a general decline in death rate in isolation.
Option C: The rate of population growth is increasing due to increase in birth rate only.
- Statement 3 explicitly states that the birth rate is declining faster than the death rate. An increasing population growth rate cannot be attributed to an increase in birth rate when the given information indicates a decline in birth rate. This option contradicts the provided facts.