Answer:
Water and sunlight are the experimental constants.
Step-by-step explanation:
As we know, scientific experiments are composed of variables (dependent and independent) that are factors that researchers can manipulate to provoke a reaction that allows them to observe results. What few know is that in addition to variables, experiments are composed of factors called "constants". Experimental constants are factors that are maintained in the same way throughout the experiment without being manipulated. An example of this can be seen in the question above, where the researcher used as constant the amount of water supplied to plants and the amount of sunlight.