**Core Concept**
The Millennium Development Goals (MDGs) were a set of eight international development goals for the year 2015 that had been established following the Millennium Summit of the United Nations in 2000. The MDGs were aimed at promoting global development and reducing poverty.

**Why the Correct Answer is Right**
The MDGs were adopted by all 191 UN member states and were designed to be achieved by 2015. The goals were to eradicate extreme poverty and hunger, achieve universal primary education, promote gender equality, reduce child mortality, improve maternal health, combat HIV/AIDS, malaria, and other diseases, ensure environmental sustainability, and develop a global partnership for development. The goals were a response to the challenges faced by the world in terms of poverty, inequality, and lack of access to basic services such as education and healthcare.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the MDGs were not established by the World Health Organization (WHO).
**Option B:** This option is incorrect because the MDGs were not focused solely on reducing child mortality.
**Option C:** This option is incorrect because the MDGs were not achieved by 2000.

**Clinical Pearl / High-Yield Fact**
It is worth noting that the MDGs were replaced by the Sustainable Development Goals (SDGs) in 2015, which are a set of 17 global goals aimed at promoting sustainable development and reducing poverty by 2030.

**Correct Answer:** D. 2015