❓ คำถาม According to the passage, why is it difficult to value ecosystem services economically?
- A. A) Because they are all indirect and take a long time to manifest.
- B. B) Because they are often public goods and not traded in markets.
- C. C) Because they are only provided by wetlands and other aquatic systems.
- D. D) Because biodiversity resilience makes them unpredictable.