Which Sentence Uses Correct Capitalization

Which sentence uses correct capitalization?

A) After serving as Congressional Aides for the summer, Kylie and Arturo learned the ins and outs of American Politics.
B) After serving as Congressional aides for the summer, Kylie and Arturo learned the ins and outs of American politics.
C) ​After serving as congressional aides for the summer, Kylie and Arturo learned the ins and outs of American politics.