The correct option is
B Nagpur
National Environmental Engineering Research Institute was established in Nagpur in the year 1958 with an aim on regulating the matters of water supply, sewage disposal, communicable diseases and industrial pollution and occupational diseases in the post-independence era of India. It was created and funded by the Government of India. It carries out research and developmental works with related affairs and falls under the Ministry of Science and Technology of Central Government. It carries out interaction programmes, conducts research for environmental science.
Hence, the correct answer is 'Nagpur'.