单选题 Which of the following best states the main point of the passage?

• (A) The approach to the problem of spatial boundaries is plagued by a number of problems that historiographers are obliged to confront.
• (B) Historiographers can benefit from studying the traditional geography of nations in greater depth.
• (C) Historiographers should try to refrain from solving the practical issues that arise in the resolution of spatial boundary issues.
• (D) The categorization and demarcations of geography at the national level is more complicated than that of the sub-national or supra-national level.
• (E) The spatial demarcation of nations is the most complicated issue in contemporary historiography.