They went through, Missouri, Kansas, Nebraska, Iowa, North and South Dakota, Montana, Idaho, Oregon, and Washington.
Basically, before 1973, the president had more power over the military and had more freedom to command the military as the president wished. This was seen in Vietnam which turned out to be a disaster. It was decided to limit the president's military power, and he would need the consent of congress to whatever operation he planned to do.
summary: limit president's military power
I'd say C because the other three wouldn't lead to it being the leading occupation, if anything, it would make it harder to conditions other than C
