Letter Writer: "In a Recent Op-Ed Piece, Your Newspaper Asserted

Letter writer: "In a recent op-ed piece, your newspaper asserted that the United States government is justified in requiring that academic researchers only receive public funding if they are not conducting research whose results may be harmful to the United States. Many researchers have proposed researching the effects of drone strikes on civilian populations in the Middle East, but have been denied any kind of federal funding to do so. Your newspaper justified this by stating that the United States needs to restrict research in order to 'ensure fundamental freedoms.' But isn't one of those fundamental freedoms the freedom to conduct research without fear of the government? I don't understand how your newspaper can put forth this opinion."
The letter writer criticizes the op-ed by:

A) Disputing the facts upon which the op-ed was based.
B) Describing an exception to the general rule described in the op-ed.
C) Pointing out an inconsistency in the op-ed.
D) Refuting an assumption upon which the op-ed was based.
E) Using an ad hominem attack on the author.