(a) In cases in which a corporation is a borrower on a section 312 loan, the Assistant Secretary for CPD or his designee may require an officer of the corporation or a principal stockholder to personally guarantee the section 312 loan or to cosign the loan note as a borrower, where necessary to make the finding of acceptable risk required for assumption of the loan.
(b) All partners of any partnership which is a borrower on a section 312 loan shall be personally liable for repayment of the section 312 loan. Limited partners shall assume personal liability by co-signing the loan note as a borrower or by personally guaranteeing the loan.
(c) Any personal guarantee or endorsement shall not relieve the partnership or corporate borrower from securing the section 312 loan by a mortgage or deed of trust on the property to be rehabilitated.