any undertaking in which a natural person or legal entity: (a) has a majority of the shareholders' or members' voting rights; or: (b) has the right to appoint or remove a majority of the members of the administrative, management or supervisory body and is at the same time a shareholder in, or member of, the undertaking in question; or: (c) is a shareholder or member and alone controls a majority of the shareholders' or members' voting rights pursuant to an agreement entered into with other shareholders or members of the undertaking