❓ 質問 According to the passage, which of the following is a reason critics oppose formally defining the Anthropocene as a geological epoch?
- A. A) The markers of human activity are not globally synchronous and thus cannot provide a clear boundary.
- B. B) Human impact on the environment is too weak to leave any permanent stratigraphic record.
- C. C) The concept has only been used informally, with no scientific literature supporting it.
- D. D) Radioactive isotopes and microplastics are not suitable as stratigraphic markers.