This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Dental
The "Human Development Index" focuses on all of the following except? 
Select and explain. 
A. Infant mortality, B. Life expectancy at birth, C. Knowledge and education, D. Gross National Income
A: Infant mortality
Answer: A: Infant mortality 
Explanation: Human Development Index (HDI) is defined as "a composite index focusing on three basic dimensions of human development to lead a long and healthy life measured by life expectancy at birth; the ability to acquire knowledge, measured by mean years of schooling and expected years of schooling; and the ability to achieve a decent standard of living, measured by gross national income per capita in PPP US $. Thus the concept of HDI reflects achievements in the most basic human capabilities, viz, leading a long life, being knowledgeable and enjoying a decent standard of living. Hence, these three variables have been chosen to represent those dimensions. The HDI is a more comprehensive measure than per capita income. Income is only a means to human development, not an end. Nor is it a sum total of human lives. Thus by focussing on areas beyond income and treating income as a proxy for a decent standard of living. the HDI provides a more comprehensive picture of human life than income does.