An example of an amendment to the U.S. Constitution that shows the principle of federalism is how the

26th Amendment allows 18-year-old citizens to vote in state and national elections
10th Amendment reserves rights to the states not assigned to the national government
16th Amendment allows the federal government to collect income taxes from individuals
First Amendment prevents states from taking away any of the people's rights to free speech

Question

An example of an amendment to the U.S. Constitution that shows the principle of federalism is how the

 26th Amendment allows 18-year-old citizens to vote in state and national elections
 10th Amendment reserves rights to the states not assigned to the national government
 16th Amendment allows the federal government to collect income taxes from individuals
 First Amendment prevents states from taking away any of the people's rights to free speech

anonymous · Answer

My guess is A, but can anyone go through these answers with me?

anonymous · Answer

The initial amendments were against the federal government primarily. Both A an C would indicate the intrusion of the federal government but C doesn't specify the interference in state authority. I vote for A that forces states to allow 18-year-old citizens to vote. Ordinarily voting is state authority. Constitutional amendments are necessary to undermine that. I suspect C is thrown in to make the choices more difficult. 

Federalism gives a federal government authority over state government. The confederation the US was before today's constitution was ratified was a democratic union with little of such federal authority.

anonymous · Answer

did you really just go and copy that from yahoo and credit it as your own? @GaleGomez

anonymous · Answer

I had forgotten to credit it, here is the link to it's rightful owner George S. https://answers.yahoo.com/question/index?qid=20120824134135AArfzce