The correct answer is: A. Form 1.
A patent application is filed on Form 1, which is a petition for a patent. The petition must be accompanied by a specification, drawings, and an oath or declaration. The specification must describe the invention in detail, and the drawings must show the invention. The oath or declaration must state that the inventor is the sole inventor of the invention and that the inventor believes the invention to be new, useful, and non-obvious.
Form 2 is a request for continued examination. This form is used to request that the USPTO continue examination of a patent application that has been abandoned.
Form 3 is a request for reconsideration. This form is used to request that the USPTO reconsider a decision that has been made in a patent application.
Form 4 is a request for reexamination. This form is used to request that the USPTO reexamine a patent that has been issued.
I hope this helps!