(C) Misrepresentation
(i) In general
Any alien who, by fraud or willfully misrepresenting a material fact, seeks to procure (or has sought to procure or has procured) a visa, other documentation, or admission into the United States or other benefit provided under this chapter is inadmissible.
(ii) Falsely claiming citizenship
(I) In general
Any alien who falsely represents, or has falsely represented, himself or herself to be a citizen of the United States for any purpose or benefit under this chapter (including section 1324a of this title) or any other Federal or State law is inadmissible.
Immigration believes that one or both of these applies to your application.
To start, are you a US citizen?