It shall be unlawful for any plan official to whom subsection (a) applies, to receive, handle, disburse, or otherwise exercise custody or control of any of the funds or other property of any employee benefit plan, without being bonded as required by subsection (a) and it shall be unlawful for any plan official of such plan, or any other person having authority to direct the performance of such functions, to permit such functions, or any of them, to be performed by any plan official, with respect to whom the requirements of subsection (a) have not been met.