successfully in such position or positions. (d) Approval of Secretary of military department Continuation of an officer on active duty under this section pursuant to the action of a selection board is subject to the approval of the Secretary of the military department concerned. (e) Nonacceptance of continuation An officer who is selected for continuation on active duty pursuant to this section, but who declines to continue on active duty, shall be discharged or retired, as appropriate, in accordance with section 632 of this title. (f) Period of continuation (1) In general An officer continued on active duty pursuant to this section shall remain on active duty, and serve in the position to which assigned (or in another position to which assigned with the approval of the Secretary of the military department concerned), for a total of not more than three years afer the date of assignment to the position to which first so assigned. (2) Additional continuation An officer whose continued service pursuant to this section would otherwise expire pursuant to paragraph (1) may be continued on active duty if selected for continuation on active duty in accordance with this section before the date of expiration pursuant to that paragraph. (g) Effect of expiration of continuation Each officer continued on active duty pursuant to this subsection who is not selected for continuation on active duty pursuant to subsection (f)(2) at the completion of the officer's term of continued service shall, unless sooner discharged or retired under another provision of law— (1) be discharged upon the expiration of the term of continued service