Explanation:

- Option 1: Radcliffe-Brown was a British social anthropologist known for his theory of structural functionalism. He didn't describe the Kula exchange.

- Option 2: Polanyi was an economic historian and anthropologist known for his work on economic systems. The Kula wasn't his area of focus.

- Option 3: Evans-Pritchard was a British anthropologist known for his work with the Nuer and Azande, not the Kula exchange.

- Option 4: Malinowski is indeed the anthropologist who described the Kula exchange system. He studied the Trobriand Islanders of Eastern New Guinea and provided a detailed ethnographic account of this ceremonial exchange system.