Section 9B. A corporation may make contracts of guarantee and suretyship, whether or not in furtherance of the contracting corporation's purposes; provided, however, that such contracts are necessary or convenient to the conduct, promotion or attainment of the business of (a) a corporation all of the outstanding stock of which is owned, directly or indirectly, by the contracting corporation, (b) a corporation which owns, directly or indirectly, all of the outstanding stock of the contracting corporation, or (c) a corporation all of the outstanding stock of which is owned, directly or indirectly, by a corporation which owns, directly or indirectly, all of the outstanding stock of the contracting corporation; provided, however, that the board of directors of the contracting corporation has determined that such contracts are necessary or convenient to the conduct, promotion or attainment of the business of the contracting corporation.