Are Magistrate Judges Article Iii Judges

what are the Article III Judges?
which of the following is not an Article III judge?
a. supreme court justice
b. court of appeals judge
c. federal magistrate
d. district judge
Please help me out here. Ive been looking for a while and cant find the answer. I swear im not just being lazy, this is from a homework assignment, but i ordered my book online and i still havent received it. its due tomorrow and the only way for me to do it is to search on google and wikipedia.
thanks in advance for your help.
The President has the power to appoint nominees to the Supreme Court, Court of Appeals, and United States District courts. Federal magistrates are voted on by District court judges so the federal magistrate is not covered by Article III.
For more information, you can visit this website. Hope this helps.
http://www.uscourts.gov/faq.html
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