Answer: C) She believes that ignorance is a desirable trait.
Step-by-step explanation: In the given excerpt from "The Importance of Being Earnest" by Oscar Wilde, we can see the description of Lady Bracknell's about she thinks ignorance is a desirable trait, because she says that if education really worked, and people weren't ignorant, they will be a threat for the upper classes and it could be the cause of violent acts, so the correct answer is option C.