What is defined as the death rate of infants less than one year old?

The correct choice is defined as the infant mortality rate, which specifically refers to the number of deaths of infants under one year of age per 1,000 live births in a given year. This metric is crucial for assessing the health and well-being of a population, as it provides insights into maternal health, quality of healthcare systems, and public health policies.

Infant mortality is a significant indicator of the overall health of a society, often reflecting conditions such as nutrition, healthcare access, and socio-economic factors. High rates of infant mortality can signal the need for interventions to improve maternal and infant health services.

The other options relate to different demographic and health statistics. Life expectancy refers to the average number of years a person can expect to live. The neonatal death rate specifically focuses on deaths that occur within the first 28 days of life, while absolute mortality generally refers to the total number of deaths in a population without specifying age groups or causes. Understanding these distinctions is important in public health and research contexts.