【題組】21. It can be inferred from the passage that Van West notes the severe droughts whichaffected the Anasazi prior to the Great Drought primarily in order to ______.
(A) establish that enough food could have been grown to support the Anasazi'ssurvival
(B) affirm the notion that the Great Drought may have been exponentially moresevere than prior droughts
(C) suggest that the repetition of droughts was taking a cumulative toll on thefertility of the Plateau
(D) argue that the Anasazi's past behavior would indicate their likely futurebehavior in the case of a Great Drought