Aisha wants to conduct an experiment to determine whether sun and shade varieties of the same plant species prefer the same wavelengths of light. She plans to measure rates of photosynthesis. Which design would be best for her experiment?
A.1 plant of the sun variety tested under blue light only, and 1 plant of the shade variety tested under blue light only.
B.4 plants of the sun variety: 1 tested under blue light, 1 under green, 1 under red, and 1 under yellow light, and 4 plants of the shade variety:1 tested under blue light, 1 under green, 1 under red, and 1 under yellow light
C.10 plants of the sun variety tested under blue light only; and 10 plants of the shade variety tested under blue light only
D.40 plants of the sun variety: 10 tested under blue light, 10 under green, 10 under red, and 10 under yellow light, and 40 plants of the shade variety: 10 tested under blue light, 10 under green, 10 under red, and 10 under yellow light.
Answer: D