25.Olivia: What’s the biggest source of pollution? The answer might surprise you. Fenny: Plastic bags? Olivia: No, throwaway diapers. Fenny: But how come they became a source of pollution? Olivia: _______________ (A) About fifty years ago. (B) They don’t break down easily. (C) Cotton diapers are good for the environment. (D) People are using fewer throwaway diapers.