Answer:
The correct answer is B) The car with normal gasoline.
Step-by-step explanation:
A control group is the one that shows "normal" or common characteristics. In this case, the normal group is the one with the usual gasoline. In other fields, the control groups could be the blank ones, like in chemistry or the average ones. In general, control groups show a pattern that could be comparable to the other ones in order to establish whether there was a change or difference or not.