What was the most important of the reform movements? explain

What would be considered as the most important reform of the Progressive movement and why?

I have to choose from: 16th, 17th, 18th and 19th amendments and direct primaries, initiatives, referendums or recall.  

This is, of course, a matter of opinion.  My own view is that, of the reforms listed here, the 19th Amendment is the most important.  This is because it did the most to right a wrong and has arguably had the greatest impact on American society.

b. martin luther king jr. wrote and spoke "i have a dream"

explanation:

i know this 100 percent is correct   b. is the best one. < 3

democracy

explanation: