Step 1: Understanding HDI.
The Human Development Index (HDI) is a composite statistic used to measure a country's overall achievement in key dimensions of human development — life expectancy, education, and per capita income.
Step 2: Global ranking.
As per the United Nations Development Programme (UNDP), Norway consistently ranks among the highest in HDI due to its high standard of living, excellent education system, and strong healthcare services.
Step 3: Conclusion.
Therefore, the country that ranks first in the Human Development Index is Norway.