A scientist wants to determine the effect of a new type of gasoline. He fills one car with normal gasoline and another identical car with the new gasoline. Which is the control group A. The amount of?

The control group in this scenario is the car filled with the normal gasoline. The control group serves as a point of reference to compare the effects of the new gasoline on the other car. It allows the scientist to identify any differences in performance that are attributable to the new gasoline rather than other factors.