According to paragraph 5, how did Dale Guthrie use the information about radiocarbon analysis of bones from Benngian deposits? A. To suggest that Colinvaux should have used different methods to measure the amount of pollen in ice-age lake sediments B. To argue that the large Beringian mammals must have eaten plants that produce little, if any, pollen C. To show that the conclusions that Colinvaux drew from the analysis of pollen in ice-age lake sediments cannot be correct D. To explain why so-called polar deserts are incapable of supporting such large animals as mammoth, horse, and bison