**Core Concept**
The National Family Health Survey (NFHS) III is a comprehensive study that assesses various health and demographic indicators across different states in India. The survey provides valuable data on socio-economic status, health outcomes, and access to healthcare services.

**Why the Correct Answer is Right**
Delhi has consistently ranked as one of the wealthiest states in India, based on various socio-economic indicators such as per capita income, literacy rate, and access to healthcare services. According to NFHS III data, Delhi's high Human Development Index (HDI) score, which takes into account factors like life expectancy, education, and income, places it among the top-performing states in the country.

**Why Each Wrong Option is Incorrect**
**Option A:** Haryana is a relatively affluent state, but its HDI score is lower than Delhi's, indicating a slightly lower standard of living.
**Option B:** Punjab, although a prosperous state, has faced challenges related to drug addiction and unemployment, which affect its overall socio-economic status.
**Option C:** Goa, although a popular tourist destination, has a relatively lower per capita income and HDI score compared to Delhi.

**Clinical Pearl / High-Yield Fact**
India's NFHS data has been instrumental in shaping national health policies and programs, highlighting the need for targeted interventions in areas like maternal and child health, nutrition, and sanitation.

**✓ Correct Answer: A. Delhi**