Which of the following is an effect of alcohol on driving skills?

Judgment impairment is a significant effect of alcohol on driving skills. When a person consumes alcohol, it affects the brain's ability to function properly, leading to poor decision-making and increased risk taking. This compromised judgment can result in an inability to assess situations accurately, causing drivers to misjudge their speed, distance, and the actions of other road users. Consequently, impaired judgment may lead to dangerous behaviors, such as speeding, aggressive driving, or failing to adhere to traffic signals and signs, all of which increase the likelihood of accidents.

In contrast, the other options describe effects that are not accurate in the context of alcohol consumption. For instance, alcohol does not increase alertness—rather, it typically causes drowsiness and reduced attentiveness. It also does not improve reaction time; in fact, it generally slows down a person's ability to respond to sudden changes on the road. Finally, alcohol does not enhance color distinction; it can instead dull the senses, making it harder to perceive colors correctly, which is critical for recognizing traffic signals and other road signs.