The book entitled 'Politics of the Kula Ring' was written by

* B. K. Malinowski is a very famous anthropologist, and his work is really important in understanding how societies work.
* The 'Kula Ring' is a system of exchange that happens in islands near Papua New Guinea.
* Malinowski spent a lot of time studying this Kula Ring and wrote a famous book about it called 'Argonauts of the Western Pacific' which describes it and is very important in anthropology.
* While the question asks about "Politics of the Kula Ring", and not "Argonauts of the Western Pacific", the book does talk about the politics involved in the Kula exchange.
* A. R. Radcliffe-Brown was another anthropologist, but his work was more focused on social structures and how societies are organized. He did not specifically study the Kula Ring.
* Peter Blau is known for his work on social exchange theory in sociology, looking at how people interact based on costs and benefits.
* Malthus is famous for his ideas about population growth and resources, not for studying specific cultures like the Kula Ring.
* J.P.S. Uberoi was an Indian sociologist and anthropologist whose work focused on kinship, family, and religion, mainly in the Indian context, and not specifically on the Kula Ring.

So, because Malinowski did significant research and is heavily linked to the study of the Kula Ring, he is the most likely answer.