Which of the following is **not** one of the leading causes of infant death?

Chronic illness is considered to be the answer because while it can affect infant health, it is not typically classified amongst the leading causes of infant death. The leading causes often include factors that are more directly linked to the prenatal and perinatal period, such as congenital abnormalities, which are structural changes present at birth, and maternal pregnancy complications that can have a direct impact on the infant's health during and after birth. Injuries also account for a significant number of infant deaths, often due to accidents or unsafe sleep practices. Chronic illnesses may affect an infant's overall health and development, but they are not predominantly recognized as a leading contributor to mortality rates in infancy when compared to the other listed factors.