Final answer:
The amount of sugar is the independent variable in the hypothesis that increasing sugar levels will make a candy bar taste sweeter.
Step-by-step explanation:
In the hypothesis 'If the amount of sugar increases then the candy bar will taste sweeter,' the independent variable is the amount of sugar. This is because the independent variable is the factor that the experimenter changes or manipulates to observe the effect on the dependent variable, which in this case would be the sweetness of the candy bar. In scientific research, it's critical to identify the independent variable correctly since it's the cause of the change, while the dependent variable is the effect or outcome that is measured.