Which is an example of a local government enforcing a national law

fayette county allows 18 year old citizens to vote.

b)
atlanta requires 18 year old males to join the military.

c)
mitchell county sets all speed limits at 55 miles per hour.

d)
savannah requires all students to attend school until they have graduated high school.

A. Fayette County allows 18 year old citizens to vote.

Explanation:

The example of a local government enforcing a national law would be when Fayette County allows 18 year old citizens to vote. The 26th Amendment lowered the voting age to 18 years around the country. Also, while 18 year old males are required to register with Selective Service, this is NOT the same thing as being registered into the military.

c. reserves power to the states and people