The number of live births per thousand persons in a year is called _____.

birth rate

The correct answer is Option (4) → birth rate

The birth rate, also known as the crude birth rate, is a demographic term that refers to the number of live births per thousand people in a population within a specific time period, usually calculated on an annual basis. It is a key indicator used in demographic studies to understand population dynamics, fertility rates, and overall population growth trends in a given region or country.