"Benzaldehyde is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful. It is a colorless liquid with a characteristic almond-like odor."
https://www.britannica.com/science/benzaldehyde
https://en.wikipedia.org/wiki/Benzaldehyde
Past climate changes led to extinction of many species, population migrations, and pronounced changes in the land surface and ocean circulation. The speed of the current climate change is faster than most of the past events, making it more difficult for human societies and the natural world to adapt.
Adenosine triphosphate (ATP) is a complex molecule which provides energy to the cells. This molecule is present in all the living organisms. The chemical energy which is obtained by the body by the breakdown of the food is captured by the ATP (Adenosine Triphosphate) molecules. This captured chemical energy is then transferred by it in order to fuel different body processes.
Hence, the answer is ATP (Adenosine Triphosphate).
It is the variable being controlled/changed to see if there are any effects on the dependent variable (the thing getting tested/measured)