Read the following paragraph carefully and select the best topic sentence from the four possible answers that follow the paragraph.
A person who has drunk too much beer gets into a strange state called drunkenness. This state is marked either by an unpleasant feeling of balance, or by falling asleep. Either of these problems is dangerous for drivers. On the road, a drunk driver is too dizzy to pay attention to traffic signs, and his lack of control may lead him to run a stop sign, exceed the speed limit, or swerve his car. As a result, he may either hit another car or a person. It is very likely that he will crash his car, and often he will kill or injure himself and others.