Each banking institution shall be a member of the Federal Deposit Insurance Corporation unless the institution is not in the business of accepting deposits or retaining funds in a deposit account. A banking institution is not in the business of accepting deposits if it accepts a deposit as a trustee or custodian and is not in the business of retaining deposits if the deposits do not remain in a deposit account of the institution for more than two consecutive banking days. Any institution which is not in the business of accepting deposits or retaining funds in a deposit account as defined in this section shall not be bound by the provisions of § 5–403(c)(2) of this title. If approved by a majority of its directors, a banking institution may: Become and participate as a member of the Federal Reserve System; or Withdraw from the system.