निम्नलिखित में से कौन सा जनसंख्या परिवर्तन के तीन मुख्य घटकों में से एक नहीं है?

Crude birth rate is defined as the number of live births per 1,000 population in:

Many developing countries experience continued population growth despite a decline in fertility rates due to which of the following factors? (a) Increase in life expectancy (b) Increase in infant mortality rate (c) Falling death rate (d) Better living conditions