Answer:
Option c. key informant interviews
Step-by-step explanation:
The work of anthropology had been hindered by many factors. For instance, the non-involvement of the researchers with the indigenous communities had hindered the access to the valuable information about the people. A typical example is of the Aborigines in Australia. By isolation, the researchers were not able to get enough information about the societies. It was only until recent studies have made efforts to include and incorporate them into the modern society.