They are releasing energy from organic molecules through aerobic respiration. In cell respiration, you are releasing energy, and in this case you are releasing energy from organic molecules. Because they are a single-celled organism using oxygen and releasing carbon, the process being used is aerobic respiration.
The plant should be de-topped at least 4 cm above the surface of the soil.
The stump of the plant is tightly fitted with the apparatus.
Tube is filled with water, not completely but at least one-fourth
Remember to note the initial water level.
Note the final water level and draw interference by calculating the difference between two levels.
I think the answer is either B or C, hope this helps! Sorry if it doesn't!