Thrips are insects that feed on rose pollen. Scientists noted that the thrips population increased in the spring and decreased dramatically during the summer. The researchers hypothesized that food abundance was the limiting factor for the population. Which of the following types of data would be most useful for the scientists to collect at regular intervals on a designated test plot of rose plants?

A. Amount of sunlight (hours/day)B. Mean temperature (°C)C. Density of rose pollen produced (g/m2)D. Amount of pollen produced by each flower (g/flower)