The Nongpok Keithelmanbi site in Manipur is notable for its:

Large bronze bells
Corded pottery tradition
Cave paintings
Iron implements

The correct answer is: a) Large bronze bells.

The Nongpok Keithelmanbi site in Manipur is a megalithic site that is notable for its large bronze bells. The bells are believed to have been used in religious ceremonies and are thought to date back to the 2nd century BC. The site is also home to a number of other artifacts, including stone tools, pottery, and human remains.

The other options are incorrect because:

  • Corded pottery is a type of pottery that is characterized by its use of corded decoration. It is not found at the Nongpok Keithelmanbi site.
  • Cave paintings are found in a number of different locations around the world, but they are not found at the Nongpok Keithelmanbi site.
  • Iron implements are found at a number of different archaeological sites, but they are not found in large numbers at the Nongpok Keithelmanbi site.