Final answer:
Of the given options, the statement that is true of Robert Costanza's valuation of ecosystem services is b. He emphasizes the monetary value of ecosystem services.
The answer is option ⇒b
Step-by-step explanation:
Robert Costanza emphasizes the monetary value of ecosystem services.
In his work, Robert Costanza recognizes the need to put a monetary value on ecosystem services to quantify the trade-offs involved in land use scenarios.
Valuing ecosystem services is the first step towards integrating these services into decision-making and ensuring the continuity of ecosystems that provide the services.
The answer is option ⇒b