Question

what impact has the minimum drinking age law had on drunk driving?
young people can only drink but not drive.
young people can only drive within city limits.
drinking rates have decreased by 15%.
less than 15% of people are caught driving drunk.

Explanation:

The minimum - drinking - age law aims to regulate alcohol consumption among young people. By setting an age limit for drinking, it can potentially reduce the number of young people who drink. If fewer young people drink, there is a likelihood that the rate of drunk driving among them will also decrease. Option "Drinking rates have decreased by 15%" is a quantitative measure that could be associated with the impact of the law.

• Option "Young people can only drink but not drive" is an over - simplification. The law is about age - restricted drinking, not a direct "drink - no drive" rule for all young people.
• Option "Young people can only drive within city limits" has no relation to the minimum - drinking - age law.
• Option "Less than 15% of people are caught driving drunk" is about the detection rate of drunk driving, not the impact of the minimum - drinking - age law on drunk driving.

Answer:

Drinking rates have decreased by 15%.