What type of vehicle were the majority of people driving when they consumed alcohol and caused a fatal collision?

The correct choice highlights that the majority of people involved in fatal collisions after consuming alcohol were driving private cars. This aligns with data showing that private cars account for a significant portion of road traffic incidents, particularly those involving alcohol consumption. The accessibility and prevalence of private cars on the road make them a common choice for individuals, and they are often more heavily associated with alcohol-related accidents compared to other vehicle types.

In contrast, while commercial trucks, bicycles, and motorcycles can also be involved in such incidents, they represent a smaller fraction compared to private car involvement. The statistics and research emphasize the correlation between alcohol consumption and the increased risk of fatality while operating private cars, making this choice not only logical but also supported by evidence from traffic incident reports.