## Core Concept
The Physical Quality of Life Index (PQLI) is an attempt to measure the quality of life or well-being of a country. It is a composite measure that averages three basic literacy, infant mortality, and life expectancy at age one.

## Why the Correct Answer is Right
The PQLI is calculated by taking the average of three indicators: literacy rate, infant mortality rate, and life expectancy at age one. These indicators are considered basic measures of a population's well-being and are used to provide a more comprehensive picture of a country's development than economic indicators alone.

## Why Each Wrong Option is Incorrect
- **Option A:** This option is not provided, but typically, literacy rate is one of the components.
- **Option B:** Similarly, this option is missing, but infant mortality rate is another component.
- **Option C:** Life expectancy at age one is also a component.
- **Option D:** Since the actual options are not provided, we assume is the correct answer and implies that one of the options (likely related to GDP, poverty rate, etc.) is not a component of PQLI.

## Why Each Wrong Option is Incorrect (Continued)
Given that actual distractors are not listed, common incorrect options would relate to economic indicators (like GDP per capita), health indicators not included (like maternal mortality), or other social determinants (like housing quality). The PQLI specifically focuses on literacy, infant mortality, and life expectancy at age one, making other indicators not part of its calculation.

## Clinical Pearl / High-Yield Fact
A key point to remember is that the PQLI was developed to provide a more nuanced view of a country's development beyond economic metrics. It is often used in discussions about human development and quality of life.

## Correct Answer: D.