The headquarters of the UNEP is located at:

Correct option is C

​The correct answer is (c) Nairobi, Kenya.

Solution:

The United Nations Environment Programme (UNEP) is headquartered in Nairobi, Kenya. 

Explanation of Other Options:

(A) Mandaluyong, Philippines: Incorrect. Mandaluyong is a city in Metro Manila, Philippines, and has no connection to UNEP headquarters.

(B) Johannesburg, South Africa: Incorrect. Johannesburg is known for hosting the World Summit on Sustainable Development (2002) .

(D) Frankfurt, Germany: Incorrect. Frankfurt is a financial hub in Europe, but it does not host UNEP headquarters.

Information Booster:

Key Details about UNEP:

• Established:1972, following the United Nations Conference on the Human Environment held in Stockholm, Sweden.
• Mandate: To monitor the global environment, provide leadership, and encourage nations to work towards sustainable development and environmental protection.
  
• ​Major Reports: Emission Gap Report,Adaptation Gap Report,Global Environment Outlook etc.
• ​The European Central Bank (ECB) has its headquarters in Frankfurt, Germany.​​