**Core Concept:** The National Family Health Survey (NFHS) is a series of nationally representative health and demographic surveys conducted in India. These surveys aim to gather data on various health-related aspects such as fertility, mortality, family planning, maternal and child health, and nutrition.

**Why the Correct Answer is Right:** NFHS-1 stands for the first phase of the National Family Health Survey, which was conducted in India in 1992. This survey helped in understanding the health and demographic conditions in India and served as a baseline for future surveys and policy development.

**Why Each Wrong Option is Incorrect:**

A. NFHS-1 was conducted in the year 2000: This is incorrect as NFHS-1 took place in 1992, not 2000.
B. NFHS-1 was conducted in the year 2005: Similar to option A, NFHS-1 occurred in 1992, not 2005.
C. NFHS-1 was conducted in the year 2000: This option repeats the mistake made in option A. NFHS-1 was conducted in 1992, not 2000.
D. NFHS-1 was conducted in the year 2005: As explained above, NFHS-1 took place in 1992, not 2005.

**Clinical Pearl / High-Yield Fact:** The NFHS series is part of the Demographic and Health Surveys (DHS) program, a global initiative that conducts similar surveys in various countries worldwide.

**Correct Answer:** NFHS-1 was conducted in the year 1992.