**Core Concept**
Infant Mortality Rate (IMR) is a widely accepted quality indicator of Maternal and Child Health (MCH) services. It measures the number of deaths of infants under one year of age per 1,000 live births in a given year. A low IMR is often considered an indicator of good quality MCH services.

**Why the Correct Answer is Right**
IMR is a sensitive indicator of the overall health status of a population, reflecting the effectiveness of prenatal, natal, and postnatal care. A low IMR suggests that the community has access to quality healthcare services, including maternal care, safe delivery practices, and pediatric care. The World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) use IMR as a key indicator to assess the progress of countries towards achieving the Sustainable Development Goals (SDGs).

**Why Each Wrong Option is Incorrect**
**Option B:** Maternal Mortality Ratio (MMR) measures the number of deaths of mothers due to pregnancy-related complications per 100,000 live births. While MMR is an essential indicator of maternal health, it does not directly reflect the quality of MCH services.

**Option C:** Child Mortality Rate (CMR) refers to the number of deaths of children under five years of age per 1,000 live births. CMR is an important indicator of child health, but it is not as specific as IMR in assessing the quality of MCH services.

**Clinical Pearl / High-Yield Fact**
IMR is a lagging indicator, meaning that it reflects the cumulative effects of past health interventions and policies. Therefore, it may take several years to see the impact of new health initiatives on IMR.

**Correct Answer Line**
✓ Correct Answer: A. IMR