**Core Concept**
The Human Development Index (HDI) is a composite statistic of life expectancy, education, and per capita income indicators, which is used to rank countries into four tiers of human development.

**Why the Correct Answer is Right**
The HDI value ranges from 0 to 1, with higher values indicating better human development. It is a logarithmic scale, meaning that small changes in the HDI value correspond to significant improvements in human development. The HDI value is calculated by taking the geometric mean of the life expectancy at birth, expected years of schooling, and gross national income per capita.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the HDI value does not lie below 0, as it is a logarithmic scale that starts from 0 but represents values above 0.
**Option B:** This option is incorrect because the HDI value does not lie above 1, as it is a normalized scale that ranges from 0 to 1.
**Option C:** This option is incorrect because the HDI value is not a ratio, but a composite index that takes into account multiple indicators.

**Clinical Pearl / High-Yield Fact**
It's worth noting that the HDI is a widely used indicator of human development, but it has its limitations. For example, it does not account for income inequality, poverty, and other social and environmental factors that can affect human well-being.

**Correct Answer: A. 0**