Question: Two identical plants are planted 3 meters apart. One plant is flowering, but the other is not. A student concludes that the plants are receiving an unequal supply of water. Another possible explanation the other plant is not flowering is that the plants are

  Options: 
 A. too close to one another.
 B. receiving different amounts of sunlight.
 C. in soil with high humus content.
 D. receiving different amounts of carbon dioxide. 
Answer: B