An advantage held by the South over the North at the start of the Civil War was B. it's soldier and generals believed they were protecting their homes and way of life. Since the South seceded from the North, all it had to do was exist to continue as an independent nation. It was up to the North to invade and restore order and thus the South was fighting a defensive war (much easier than the opposite - an offensive war).
No, the Monroe Doctrine does not provide U.S. sympathy for the new revolutionary governments in South America. You're thinking of the "Good Neighbor" policy.
