(a) The following subjects may be discussed in an executive session:
(1) Matters the immediate knowledge of which would clearly have an adverse effect upon the finances of the government unit;
(2) Subjects that tend to prejudice the reputation and character of any person, provided the person may request a public discussion.
(b) The following shall be discussed in executive session when the best interests of the city so require:
(1) Negotiations with labor organizations representing city employees;
(2) Discussions of pending or threatened lawsuits in which the city has an interest.
(c) If excepted subjects are to be discussed at a meeting, the meeting must first be convened as a public meeting, and the question of holding executive session to discuss matters that come within the exceptions contained in divisions (a) and (b) of this section shall be determined by a vote of the body. No subjects may be considered at the executive session except those mentioned in the motion calling for the executive session unless pertaining to the main question. No action may be taken at the executive session.