Subject to section 138, a person who elects, or is taken to have elected, under section 132 to become a member of the MSB scheme ceases, or is taken to have ceased, to be an eligible member of the Defence Force:
(a) if the election is made, or is taken to have been made, on or before 30 September 1991--at the end of that day; or
(b) if paragraph (a) does not apply--at the end of the day on which the election is made or is taken to have been made.