The session of a PCA church calls a congregational meeting for the stated purpose of making an announcement and explaining a sessional decision. After this announcement there is a motion from the floor to open the floor for discussion on the issue. There is a second. The clerk states that there can be no such discussion, citing the Book of Church Order, saying that no business may take place except that which was in the stated purpose of the meeting. The members claim that with a proper motion and second, discussion must be allowed. Who's right?