Context: Emmy wants to grow sunflowers in her backyard garden. She notices that some sunflowers grow much taller than others. She is curious about what factors affect how sunflowers grow. So, she decides to design an experiment. She has the following supplies available:
seeds from one type of sunflower
soil
one wooden planter box in the sun
one wooden planter box in the shade
one plastic planter box in the sun
water
Using only these supplies, which question can Emmy investigate with an experiment?
A. Do sunflowers grow taller if they are planted in planter boxes or in pots?
B. Do sunflowers grow bigger in sunny planter boxes or in shady planter boxes?
C. Which type of sunflower grows more leaves?
Answer with the option's letter from the given choices directly.

B