Correct answer choice is:
B. Time
Explanation:
Primary productivity is a phrase applied to define the frequency at which plants and other photosynthetic bodies generate natural compounds in an ecosystem.
There are two features of primary productivity:
Gross primary production is the entire quantity of organic substance manufactured in a given time, whereas net primary production is the quantity of organic substance produced in abundance of that practiced in respiration.
Answer: b. time
Primary productivity can be defined as the production of the organic matter or biomass by the living plants and other autotrophs in the food chain. It depends upon the availability of the sunlight, availability of the nutrients such as nitrogen, iron, phosphorous from the soil and water. The biomass produced by primary productivity is available for the consumption of the next trophic level called as consumers.
The primary productivity of the plants other autotrophs is not limited by the time but can be limited by the lack of sunlight, nutrients and water.
