According to the provisions of the Patent Law, if a patent right is transferred, the effective date of the transfer of the patent right is ( ).

Answer: B

Article 10, paragraph 3, of the Patent Law stipulates that when transferring patent application rights or patent rights, the parties shall enter into a written contract and submit it to the Patent Administration Department of the State Council. Registration shall be announced by the patent administration department of the State Council. The transfer of patent application rights or patent rights takes effect from the date of registration. Accordingly,