The three correct answers that accurately describe coral reefs are:
- Coral reef ecosystems are among the most biodiverse on Earth.
- Coral reefs are located in nutrient-rich waters.
- Coral reefs are sturdy structures that can exist for thousands of years.
Coral reefs are not delicate structures that exist for less than 10 years, and they do not typically thrive in nutrient-poor waters—rather, they are commonly found in nutrient-rich environments that also have certain conditions suitable for their growth.