In a recent study, researchers grew rice in chambers with varying levels of carbon dioxide (CO₂) to simulate different atmospheric conditions. They found that as CO₂ levels increased, the nutritional content of the rice changed. Specifically, the rice contained less protein, iron, and zinc, but contained more carbohydrates. One potential explanation for these findings is that, since CO₂ is an important input to photosynthesis, the elevated carbon dioxide levels could be spurring the plants to photosynthesize more rapidly. This, in turn, could lead to increased carbohydrate production at the expense of other nutrients like protein, iron, and zinc.
Which of the following is a potential explanation for the changes observed in the nutritional content of rice as CO₂ levels increase?

A) Increased carbohydrate production due to elevated CO₂ levels
B) Decreased carbohydrate production due to elevated CO₂ levels
C) Decreased protein production due to decreased CO₂ levels
D) Increased iron production due to increased CO₂ levels