短篇阅读
Although passenger pigeons, now extinct, were abundant in eighteenth-and nineteenth-century America, archaeological studies at twelfth-century Cahokian sites in the present-day United States examined household food trash and found that traces of passenger pigeon were quite rare. Given that the sites were close to a huge passenger pigeon roost documented by John James Audubon in the nineteenth century and that Cahokians consumed almost every other animal protein source available, the archaeologist conducting the studies concluded the passenger pigeon population had once been very limited before increasing dramatically in post-Columbian America. Other archaeologists have criticized those conclusions on the grounds that passenger pigeon bones would not be likely to be preserved. But all the archaeological projects found plenty of bird bones--and even some tiny bones from fish.
The author of the passage mentions "tiny bones from fish" primarily in order to
A. Explain why traces of passenger pigeon are rare at Cahokian sites
B. Support a claim about the wide variety of animal proteins in the Cahokian diet
C. Provide evidence that confirms a theory about the extinction of the passenger pigeon
D. Cast doubt on the conclusion reached by the archaeologists who conducted the studies discussed in the passage
E. Counter an objection to an interpretation of the data obtained from Cahokian sites
答案：C