A. Money in the student loan sinking fund and money in the student loan fund in excess of the amount necessary for student loans may be invested by the state treasurer in:
(1) direct obligations of, or obligations whose principal and interest are guaranteed by, the United States;
(2) direct obligations of, or participation certificates guaranteed by, the federal intermediate credit bank, federal land banks, federal national mortgage association, federal home loan banks or banks for cooperatives;
(3) certificates of deposit of any bank or trust company whose deposits are fully secured by a pledge of securities of any kind specified in this subsection; and
(4) bonds of the state or its political subdivisions.
B. Money in the student loan sinking fund may be invested only in obligations which are scheduled to mature prior to the date the money must be available for its intended purpose.
C. All investments under this section may be sold at the prevailing market price. Income from these investments shall be credited to the student loan sinking fund.