【单选题】The author of the passage mentions the ' 'professional primitive' role' (line 15) assumed by foragers in their relationships with agriculturalists primarily in order to
A.
inform. the reader of the potential cause of certain changes in rain forest composition
B.
suggest that foragers may have developed agricultural practices, then abandoned them in order to focus on more specialized food-gathering practices
C.
explain why certain food gathering practices may be less efficient sources of carbohydrates than others
D.
introduce new evidence for the interdependence between agriculturalists and foragers in the rain forest economy
E.
suggest that certain rain forest food products are healthier than others, though more difficult to obtain through foraging