The Millennium Ecosystem Assessment describes the following major categories of ecosystem services-provisioning, supporting, regulating, preserving and cultural. Which one of the following is supporting service?

1. The Millennium Ecosystem Assessment (MEA) framework categorizes ecosystem services into four major types: provisioning, regulating, cultural, and supporting services. (Note: 'Preserving' is not a standard MEA category, though conservation underlies all services). 2. Supporting services are those that are necessary for the production of all other ecosystem services. They provide the fundamental ecological functions and processes. 3. Option (A) 'Production of food and water' are direct products obtained from ecosystems, hence they are Provisioning services. 4. Option (B) 'Control of climate and disease' are benefits obtained from the regulation of ecosystem processes, hence they are Regulating services. 5. Option (C) 'Nutrient cycling and crop pollination'. Nutrient cycling is a fundamental biogeochemical process essential for plant growth. Crop pollination is a process carried out by organisms (supported by the ecosystem) that enables the production of food (a provisioning service). Both are classic examples of Supporting services because they underpin other services. 6. Option (D) 'Maintenance of diversity' (biodiversity) is crucial for the resilience and functioning of ecosystems and supports many other services. It is often considered intrinsically linked to or as a part of supporting services, but Nutrient cycling and pollination are more direct operational examples provided in the MEA framework. 7. Therefore, 'Nutrient cycling and crop pollination' is the correct answer representing supporting services.