(a) In accordance with a written policy approved by the governing body of the public entity, a public entity shall determine if an investment security is eligible to secure deposits of public funds.
(b) The written policy may include:
(1) the security of the institution that obtains or holds an investment security;
(2) the substitution or release of an investment security; and
(3) the method by which an investment security used to secure a deposit of public funds is valued.