In the field, ethnographers strive to establish rapport: a good, friendly working relationship, ...

In the field, ethnographers strive to establish rapport: a good, friendly working relationship, based on personal contact,
 
  A. that is necessary in conducting any valuable research in the social sciences, not just anthropology.
  B. that if done properly ensures the ethnographer's ability to conduct detached, unbiased research.
  C. achieved in large part by engaging in participant observation.
  D. and if that fails, the next option is to pay people so they will talk about their culture.
  E. as well as on payment, based on local standards, for people's time spent with the researcher.