(a) General rule.— A plan shall be approved in the case of a domestic general partnership as follows:

1. (1) in the manner provided in its organic rules for the type of plan involved;
2. (2) if its organic rules do not provide for approval of the type of plan involved, in the manner provided in its organic rules for approval of a plan of merger; or
3. (3) if its organic rules do not provide for approval of the type of plan involved or a plan of merger, the plan shall be approved by all of the partners.