Answer
(c)
Work Step by Step
I. Ecosystem service - Primary production (photosynthesis by plants, algae, and some bacteria) is a provisioning service that supports food webs and carbon cycling. It’s essential for producing oxygen and biomass.
II. Environmental indicator - Rates of primary production can reflect ecosystem health, nutrient availability, and climate conditions. Scientists use it to monitor changes in aquatic and terrestrial systems.
III - Heterotrophic activity - Primary production is autotrophic activity (organisms produce their own energy), not heterotrophic.
The answer is (c).
