A student sets up a photosynthesis experiment using two iden…

A student sets up a photosynthesis experiment using two identical test tubes containing aquatic plants and a carbon dioxide indicator solution (e.g., bromothymol blue): Tube 1 is placed in bright light Tube 2 is placed in complete darkness After several hours, the student observes the following: Tube 1: The solution turns blue Tube 2: The solution turns yellow What is the best explanation for these observations? A) Tube 1 absorbed more water, which caused the indicator to change color.B) Tube 2 produced more oxygen, increasing the pH of the solution.C) Tube 1 underwent photosynthesis, removing CO₂ and raising the pH.D) Tube 2 absorbed more carbon dioxide, decreasing the pH.