Answer: C
Explanation: process of elimination
a.understand the moral of the story- the elephant part has nothing to do with the moral of "you can use your brain to solve problems"
b.appreciate elephants and their relationship to trees- the elephant part doesn't have anything about why elephants are important, or why they should be appreciated
d.appreciate Sally's unique goals- the elephant part doesn't explain what Sally's goals are
c.understand just how big the branch is compared to Sally- elephants are huge, and saying something is like an elephant or as big as an elephant is another way of saying that it's really big