Answer:
The correct answer will be option-D
Explanation:
The aerotaxis movement experiment performed by the Theodor W. Engelmann played an important role in understanding the photosynthesis.
The experiment was performed on the Spirogyra filamentous algae which were exposed to a different wavelength of light.
The other aerobic bacteria present in the test tubes started moving and accumulated near the two regions of the Spirogyra where they were exposed to the blue and red light of the VIBGYOR.
The region receiving red and blue light produced more oxygen through photosynthesis which indicated that these two wavelengths of the light are more active for photosynthesis than any other wavelengths.
Thus, option-D is the correct answer.