Unless otherwise specified by a provision of the Revised Code or this section, a surviving spouse shall exercise all rights under Chapter 2106 of the Revised Code within five months of the initial appointment of an executor or administrator of the estate. It is conclusively presumed that a surviving spouse has waived any right not exercised within that five-month period or within any longer period of time allowed by the court pursuant to this section. Upon the filing of a motion to extend the time for exercising a right under Chapter 2106 of the Revised Code and for good cause shown, the court may allow further time for exercising the right that is the subject of the motion.