Answer:
The type of soap should remain the same, but the temperature of the water should change.
Step-by-step explanation:
According to the observation, question and hypothesis of this investigation, it can be determined that the variable being tested called INDEPENDENT VARIABLE is the temperature of the water while the effect is being measured on the amount of bubbles produced called the DEPENDENT VARIABLE.
The independent variable is the variable that the experimenter changes or manipulates in an experiment. Hence, in this case, the temperature of the water should change. On the other hand, the variable that should remain the same or constant is called CONSTANT VARIABLE. In this experiment, the type of soap used should remain the same so as not to affect the outcome of the experiment.