**Core Concept**
The World Health Organization (WHO) is a specialized agency of the United Nations responsible for international public health. The WHO constitution serves as the foundation for its activities and goals, outlining the organization's purpose, principles, and functions.

**Why the Correct Answer is Right**
The WHO constitution was adopted on July 22, 1946, at the International Health Conference held in New York City. This constitution has been amended several times since its adoption, with the most recent amendment taking place in 2005. The constitution emphasizes the importance of international cooperation in achieving the highest possible level of health for all people, with a focus on promoting health, preventing disease, and providing medical care.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the WHO constitution was not adopted in the city of Paris. While the WHO is headquartered in Geneva, Switzerland, the constitution was adopted in New York City.
**Option B:** This option is incorrect because the WHO constitution was not adopted in the year 1945. Although the conference that led to the adoption of the constitution took place in 1946, the actual adoption occurred later that year.
**Option C:** This option is incorrect because the WHO constitution was not adopted in the city of Geneva, Switzerland. While the WHO is headquartered in Geneva, the constitution was adopted in New York City.

**Clinical Pearl / High-Yield Fact**
The WHO constitution has undergone several amendments since its adoption, with the most recent amendment in 2005. This highlights the dynamic nature of the organization and its commitment to adapting to changing global health needs.

**Correct Answer: C. 1946**