(1) A plan of merger must be adopted in the following manner:
(a) If the members of any merging corporation are entitled to vote on a plan of merger, the board of directors of such corporation must adopt a resolution approving the proposed plan and directing that it be submitted to a vote at a meeting of members entitled to vote on the proposed plan, which may be either an annual or special meeting. Written notice setting forth the proposed plan or a summary thereof must be given to each member entitled to vote at such meeting in accordance with the articles of incorporation or the bylaws. The proposed plan shall be adopted upon receiving at least a majority of the votes which members present at each such meeting or represented by proxy are entitled to cast; or
(b) If a merging corporation has no members or if its members are not entitled to vote on a plan of merger, such plan may be adopted at a meeting of its board of directors by a majority vote of the directors then in office.
(2) Unless a plan of merger prohibits abandonment of the merger without approval by the members entitled to vote on the plan of merger, after authorization for a planned merger by a vote of members, the board of directors may, in its discretion, abandon such planned merger, subject to the rights of third parties under any contracts relating to the planned merger, at any time prior to the filing of articles of merger by any corporation party to the merger without any further action or approval by the members.