(a) Any state or national bank doing business in the state may be designated by the comptroller as a state depository. Designation of a bank as a depository includes all of the bank's branches within the state.
(b) Any savings and loan association doing business in the state may be designated by the comptroller as a state depository.
(c) Any state or federal credit union doing business in the state may be designated by the comptroller as a state depository.
(d) Deposits of eligible institutions designated as state depositories must be covered by the Federal Deposit Insurance Corporation or the National Credit Union Share Insurance Fund.