**Core Concept**
The Physical Quality of Life Index (PQLI) is a composite indicator used to measure the well-being or quality of life of a country, focusing on basic needs such as literacy rate, infant mortality rate, and life expectancy at age one.

**Why the Correct Answer is Right**
The PQLI is a quantitative measure that combines three essential components: literacy rate, infant mortality rate, and life expectancy at age one. These indicators are used to assess the physical quality of life, reflecting a country's ability to meet its citizens' basic needs. The PQLI score ranges from 0 to 100, with higher scores indicating better quality of life.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect as it is a different quality of life index that focuses on economic and social factors.
**Option B:** This option is incorrect as it is a measure of healthcare access and outcomes, not a comprehensive quality of life index.
**Option C:** This option is incorrect as it is a measure of income inequality, not a quality of life index.

**Clinical Pearl / High-Yield Fact**
The PQLI is a useful tool for policymakers and researchers to evaluate the effectiveness of development programs and track progress towards achieving the United Nations' Sustainable Development Goals (SDGs).

**Correct Answer:** None given (please provide the correct answer options for a complete explanation)