The correct answer is "B".
Primary productivity is the rate at which plants produce organic compounds in an ecosystem. The elements that serve as parameters, in other words, restraint the production of organic compounds are:
- Sunlight, as it is the essential energy source for the synthesis to occur.
- Nutrients which are located in the soil are essential for the plant's survival.
- Availability to water, as it is an essential resource need for a plants subsistence.