Which of the following statements concerning the Basseri and the Qashqai is true?

A. Both were nomadic foraging groups in Iran.

B. A symbiotic relationship existed between the Basseri, who were nomadic pastoralists, and the Qashqai, who were horticulturalists.

C. The Basseri "big man" (tonowi) could enforce his decisions, whereas the Qashqai village head could only lead by example.

D. The Qashqai authority structure was more complex and hierarchical than that of the Basseri.