Sec. 11.01. INVESTMENTS. The board of trustees in its sole discretion may invest, reinvest, or change the assets of the fund. The board of trustees shall invest the funds in whatever instruments or investments the board considers prudent. In making investments for the fund, the board of trustees shall discharge its duties with the care, skill, prudence, and diligence under the circumstances then prevailing that a prudent person acting in a similar capacity and familiar with such matters would use in the conduct of an enterprise of a similar character and with similar aims.