Why does the author of "the think tank" include shumaker's admission that he did not think that azy would be the fastest learner? a. to show that shumaker used to dislike working with azy b. to show that azy only began to improve as a learner when shumaker started to work with him c. to show that animals can even surprise experts with their capacity to learn d. to show that researchers must sometimes do work that they consider difficult