The insurance authorized by this part may be provided by:
(a) Self-insurance, which may be, but is not required to be, funded by appropriations to establish or maintain reserves for self-insurance purposes.
(b) Insurance in any insurer authorized to transact such insurance in this state.
(c) Insurance secured in accordance with Chapter 6 (commencing with Section 1760) of Part 2 of Division 1 of the Insurance Code.
(d) Participation by a hospital district and its medical staff in a reciprocal or interinsurance exchange as provided in Section 1284 of the Insurance Code.
(e) Any combination of insurance authorized by subdivisions (a), (b), (c), and (d).