The correct answer is A. The control group
Step-by-step explanation:
In an experiment, the control group refers to the participants that do not receive special treatment or receive a placebo, which does not affect them. On the opposite, the experimental group includes the participants that are given special treatment. For example, to test the effects of medicine the experimental group will be given the medicine, while the control group will be given a placebo. This is important because the control group allows researchers to understand the real effect of the medicine or factor that is tested.
According to this, in the case presented those that smoke the fake cigarette or cigarette without nicotine are the control group because, in opposition to those that smoke a real cigarette, they do not have a special treatment but only serve as a standard to understand the effect of the real cigarettes in the number of collisions while driving.