Final answer:
In the given hypothetical statement, 'Exercise' is the Independent Variable since it is what is being manipulated to observe its effect on health, the dependent variable.
Step-by-step explanation:
In the hypothetical statement If I exercise regularly, then I will be healthier, the Independent Variable is: a) Exercise. This is because the independent variable is the condition or factor that is manipulated by the researcher to determine its effect on another variable, which in this case is health. The outcome, or what is being measured, is the dependent variable, which is health in this scenario.