A credit union shall keep the books and records that the Commissioner requires to determine compliance with this title. Unless a longer period is expressly required by State or federal law, a credit union shall retain the books and records required under subsection (a) of this section for a period of at least 5 years. A credit union may retain the books and records required under subsection (a) of this section at any location, provided that the credit union: Notifies the Commissioner in writing of the location of the books and records; and Makes the books and records available at the credit union’s principal place of business, as agreed by the Commissioner and the credit union, within 7 days of a written request for examination by the Commissioner. A credit union shall retain the books and records required under subsection (a) of this section in one of the following ways: Original form; An electronic equivalent approved by the Commissioner; or A microphotographic copy approved by the Commissioner.