**Core Concept**
The Physical Quality of Life Index (PQLI) is an attempt to quantify the quality of life in a country, taking into account factors such as literacy rate, infant mortality rate, and life expectancy at age one. It is a composite index that aims to provide a more nuanced understanding of a country's well-being beyond mere GDP.

**Why the Correct Answer is Right**
The PQLI is a more comprehensive measure of a country's quality of life, as it incorporates both social and health indicators. It is calculated by assigning weights to literacy rate (25%), infant mortality rate (25%), and life expectancy at age one (50%), and then averaging these values to obtain a single index score. This approach allows for a more detailed understanding of a country's strengths and weaknesses in terms of its quality of life.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because it does not accurately describe the PQLI. While the PQLI does take into account social and health indicators, it is not simply a measure of a country's economic growth.
**Option B:** This option is incorrect because it is not a valid component of the PQLI. The PQLI includes literacy rate, infant mortality rate, and life expectancy at age one, but not economic growth rate.
**Option C:** This option is incorrect because it does not accurately describe the PQLI's focus on quality of life. While the PQLI does take into account health indicators, it is not solely focused on healthcare.

**Clinical Pearl / High-Yield Fact**
The PQLI is an example of a composite index, which is a statistical tool used to combine multiple indicators into a single score. This approach allows for a more nuanced understanding of a country's strengths and weaknesses, and can be useful in evaluating the effectiveness of development programs.

**Correct Answer:** D