shall be automatically declassified on December 31 of the year that is 50 years after the date on which the records were created, whether or not the records have been reviewed. (2) Postponement (A) Agency Postponement The head of an agency may postpone automatic declassification under paragraph (1) of specific records or information, or renew a period of postponed automatic declassification, if the agency head determines that disclosure of the records or information would clearly and demonstrably be expected— (i) to reveal the identity of a confidential human source or a human intelligence source