Answer: C. It just thrills me that we have so much waste in landfills.
In this sentence, the author uses a sarcastic remark. Sarcasm refers to a sharp expression that usually shows an ambivalence similar to irony. Sarcasm is usually an ironic remark in which the speaker does not mean what he says. It is usually intended to mock or express contempt. In this case, the speaker is saying he is thrilled to have so much waste in landfills. This is likely to be false. Moreover, it is intended to criticize the problem of waste in our society.