Answer
D, primary consumer efficiency would be affected by nutrient availability, amount of sunlight, and temperature.
Work Step by Step
If a consumer is efficient, there has to be abundant amounts of nutrients which the organism could intake and turn into energy. The organism must also need a high amount of sunlight to help with photosynthesis; low sunlight levels would lead to a slower photosynthesis rate. Finally, the productivity would also be affected by temperature, for the higher the temperature, the faster the molecular processes will take place.
