A map of North America with international borders, state borders and province borders is shown. The map legend displays four types of borders. State and province borders are shown as a thin black line. International borders are shown with thick dark lines. State river boundries are shown with a thin blue line and International river boundries are shown with a thick blue line. Which of the following is a true statement about the map?

A The border between Canada and North Dakota is a thick, black line; this indicates a national boundary.
B The border between Montana and North Dakota is a thin, black line, this indicates a national boundary.
C The border between Montana and North Dakota is a thin, blue line; this indicates a state boundary.
D The border between Canada and North Dakota is a thin, black line; this indicates a national boundary.

Civics