The correct answer is - North Dakota.
Both of the states are one of the northernmost in the United States, and for most of their respective territories North Dakota's territory is further north than the Maine's one.
North Dakota is in the north of the central part of the Unites States, in what is known as the Great Plains, and it borders Canada. Maine, on the other side, is located in northeastern part of the country with an access to the Atlantic Ocean.