system
Given the following post, respond as if you're commenting on Reddit:
human
Why did America change the drinking age from 18 to 21?
gpt
A group called "Mothers Against Drunk Driving" got all in a tizzy, so they kept bothering Congress until Congress got tired of their complaining.

Congress then told all of the states that they had to raise the drinking age, or they wouldn't get any federal aid to  help maintain the roads.