under this section shall be subject to the approval of the Secretary to ensure that such use is designed to retrofit units that are currently obsolete or unmarketable. (9) Repayment of assistance and prevention of undue benefits (A) Repayment If a recipient, or a project sponsor receiving funds from the recipient, receives assistance under subsection (b) for use pursuant to paragraph (2) of such subsection for the construction, acquisition, or rehabilitation of supportive housing for very low-income veteran families and the project ceases to provide permanent housing, the Secretary shall require the recipient, or such project sponsor, to repay the following percentage of such assistance: (i) In the case of a project that ceases to be used for such supportive housing before the expiration of the 10-year period beginning upon commencement of the operation of the project, 100 percent. (ii) In the case of a project that ceases to be used for such supportive housing on or after the expiration of the 10-year period beginning upon commencement of the operation of the project, but before the expiration of the 15-year period beginning upon such commencement, 20 percent of the assistance for each of the years during such 15-year period for which the project fails to provide permanent housing. (B) Prevention of undue benefits Except as provided in paragraph (C), if any property is used for a project that receives assistance under subsection (b) for use pursuant to paragraph (2) of such subsection for the construction, acquisition or rehabilitation of supportive housing for very low-income veteran families, and the sale or other disposition of the property occurs before the expiration of the 15-year period beginning upon commencement of the operation of the project, the recipient (or the project sponsor receiving funds from the recipient) shall comply with such terms and conditions as the Secretary may prescribe to prevent the recipient (or such project sponsor) from unduly benefitting from such sale or disposition. (C)