Q: Fact 1: Biodiversity increases the productivity and stability of ecosystems. Fact 2: Ecotourism, on the other hand, can help to conserve biodiversity. Given the two facts above, what increases the stability of ecosystems?

Choose your answer from: 1. overpopulation 2. water consumption 3. loose soil 4. Quality of life 5. agriculture 6. deforestation 7. ecotourism 8. trees
The answer is:
7.