The statement that best supports the author's argument that his papers are insignificant is A: "I don't think that our Commonwealth would have been shaken to its foundations if they had been handed in the moment after."
This line illustrates his belief that the content of the papers is not of great importance or significance; if the papers were not published immediately, it would not have a substantial impact on society or the Commonwealth. The other options provide context to his feelings about the papers but do not directly express the insignificance of their content in the same way.