The following proceedings set forth in this section are exempt from the Ralph M. Brown Act (Chapter 9 (commencing with Section 54950) of Part 1 of Division 2 of Title 5 of the Government Code), unless the parties mutually agree otherwise:
(a)
Any meeting and conferring discussion between a transit district employer and a recognized or certified employee organization.
(b)
Any meeting of a mediator with either party or both parties to
the meeting and conferring process.
(c)
Any hearing, meeting, or investigation conducted by a factfinder or arbitrator.
(d)
Any executive session of the transit district employer or between the transit district employer and its designated representatives for the purpose of discussing its position respecting meeting and conferring or regarding any matter within the scope of representation or instructing its designated representatives.