Answer:
I think the full question is this:
The pH indicator bromothymol blue is blue in an alkaline solution and yellow in an acidic solution. A slight increase in acidity, such as when CO2 gas is added, causes a solution with the indicator to change from blue to yellow. A solution with the indicator would be most likely to turn from yellow to blue when which combination of factors exists? A. Yeast cells and sugar are placed in the solution. B. Water plants in the solution are placed under a bright lamp. C. Algae are placed in the solution and left in a dark room. D. A person blows air into the solution through a straw.
Answer is option B
B. Water plants in the solution are placed under a bright lamp.
Explanation:
When CO2 gas was added, it causes a solution with the indicator to change from blue to yellow. A combination of factors that can cause this solution to change from the yellow to its initial blue colour is utilizing a photosynthetic organism which in the presence of light can utilize and remove these carbondioxide and revert the yellow colour of the solution to blue
Thus, water plants in the solution are placed under a bright lamp
Algae are placed in the solution and left in a room filled with light