Answer :
The most likely reason why the U.S. has a lower percentage of adults with a college education is that college education is quite expensive in the U.S.
Why are U.S. college rates lower than many countries?
In the U.S., college tuition fees and other fees related to attending college, are some of the highest in the world.
As a result, a lot of people tend to avoid going to college because they can't afford to pay those college fees.
Find out more on college fees at https://brainly.com/question/9299811.