Please Use the Following Information to Answer the Question(s) Below

Please use the following information to answer the question(s) below.
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 found 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 a local increase in temperature generated by illumination by red and blue light.
B) Bacteria released excess carbon dioxide in these areas.
C) Bacteria congregated in these areas because they are attracted to red and blue light.
D) Bacteria congregated in these areas because they were the areas where the most oxygen was released by the algae.
E) Bacteria congregated in these areas because green, yellow, and orange light inhibits bacterial metabolism.