Final answer:
Ecosystem services are essential services provided by nature, critical for human survival and the well-being of the planet, with the correct answer being option d- nature that benefits mankind.
Step-by-step explanation:
Ecosystem services are services provided by nature that benefit mankind. These include but are not limited to the purification of air and water, generation of oxygen, climate stabilization, decomposition and detoxification of waste, nutrient recycling, soil formation, pollination of crops, and flood mitigation. Humans deeply rely on these services for survival, and ecosystems play a fundamental role in sustaining human life and the well-being of our planet. While these services are invaluable, recent studies highlight the importance of quantifying and valuing ecosystem services to integrate them into public decision-making and to avoid the degradation of these essential natural functions, often referred to as the 'tragedy of the commons'.
Therefore, the correct answer to the student's question is option d. nature that benefits mankind' as ecosystems inherently offer a multitude of services that are critical for the survival of all living organisms on Earth.