(a) The board of trustees shall maintain responsibility for all money collected or disbursed from the group.(b) The board shall annually adopt a written investment plan consistent with the requirements for the investments authorized under Insurance Code Article 2.10 and §822.204 for minimum capital and surplus and reserves. The investment plan shall meet the requirements of Insurance Code Article 2.10(a).(c) With the prior written approval of the Commissioner, a group may invest up to 5% of its assets in a manner other than that authorized under this section.(d) The group shall hold all investments in accordance with Texas Insurance Code Article 21.39B.