Which of the following woud be expected to have the greatest impact on primary productivity? a chemical energy b nutrient availability c solar energy d water availability

C solar energy

Solar energy has the greatest  impact on primary productivity.

Explanation:

Primary productivity  is the amount of organic compounds synthesized from carbon dioxide. Primary production occurs by the process of photosynthesis. Since the process of photosynthesis uses sunlight as the energy source solar energy has the greatest impact on primary productivity.

The synthesis can occur in atmosphere as well as aquatic environment. The organisms that perform the function of primary production are called producers .In terrestrial regions plants are the producers and in aquatic systems algae are the  primary producers.