Theodor W Engelmann Illuminated a Filament of Algae with Light That

Theodor W. Engelmann illuminated a filament of algae with light that passed through a prism, thus exposing different segments of algae to different wavelengths of light. He added aerobic bacteria and then noted in which areas the bacteria congregated. He noted that the largest groups were found in the areas illuminated by the red and blue light. What did Engelmann conclude about the congregation of bacteria in the red and blue areas?

A) Bacteria congregated in these areas due to an increase in the temperature of the red and blue light.
B) Bacteria congregated in these areas because these areas had the most oxygen being released.
C) Bacteria are attracted to red and blue light and thus these wavelengths are more reactive than other wavelengths.
D) Bacteria congregated in these areas due to an increase in the temperature caused by an increase in photosynthesis.