The best answer, by far, is D. That is the main purpose of the Supreme Court: to protect the Constitution.
A is definitely wrong. Sometimes the findings affect very large groups of people like Dred Scott or some of the Education decisions (which have to do with segregation).
B might be true but it is not nearly as important as D.
C is totally incorrect. Perhaps there was a case of two involving press gangs, but I can't find anything -- even during the 1812 war where impressment was a major issue (done by Great Britain to American Sailors).
