Correct Answer:
C. New Zealand
The correct answer is New Zealand. New Zealand has been a global leader in environmental law, notably granting legal personhood to the Whanganui River and Te Urewera National Park. While the question specifies 2025 for 'full legal rights to ecosystems,' New Zealand's progressive legal framework for nature makes it the most plausible country to take such a pioneering step. Costa Rica is renowned for its environmental protection but has not specifically granted full legal rights to ecosystems in this manner. Canada has not implemented similar legislation. Therefore, options A, B, and D are incorrect.