Statement 1: ‘Population explosion’ happens because death rates are brought down relatively quickly through advanced methods of disease control, public health, and better nutrition.
Statement 2: In India, the demographic transition is completed as the mortality rate has been reduced but the birth rate has not been brought down to the same extent.

Only statement 1 is correct.

The ‘population explosion’ happens because death rates are brought down relatively quickly through advanced methods of disease control, public health, and better nutrition. However, it takes longer for society to adjust to change and alter its reproductive behaviour (which was evolved during the period of poverty and high death rates) to suit the new situation of relative prosperity and longer life spans. This kind of transition was effected in Western Europe during the late nineteenth and early twentieth century. More or less similar patterns are followed in the less developed countries that are struggling to reduce the birth rate in keeping with the falling mortality rate. In India too, the demographic transition is not yet complete as the mortality rate has been reduced but the birth rate has not been brought down to the same extent.