Which of the following of Calpurnia's lines is the best demonstration that she understands the limitations of her society very clearly?

a) "It's the same God, ain't it?" (158)

b) "Folks aren't anxious to--to have anything to do with the family" (164)

c) "They'd think I was puttin' on airs to beat Moses" (167)

d) "they've got to want to learn themselves, and when they don't want to learn there's nothing you can do but keep your mouth shut" (167)