Except as otherwise provided by law, the board and its officers and employees of the system shall not cause the system to engage in a transaction if they know or should know that the transaction constitutes a direct or indirect: (

a) Sale or exchange, or leasing, of any property from the system to a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, for less than adequate consideration, or from a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, to the system for more than adequate consideration. (

b) Lending of money or other extension of credit from the system to a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, without the receipt of adequate security and a reasonable rate of interest, or from a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, with the provision of excessive security or an unreasonably high rate of interest. (

c) Furnishing of goods, services, or facilities from the system to a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, for less than adequate consideration, or from a member, or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, to the system for more than adequate consideration. (

d) Transfer to, or use by or for the benefit of, a member or beneficiary of the Defined Benefit Program, as well as a participant or beneficiary of the Cash Balance Benefit Program, of any assets of the plan for less than adequate consideration. (

e) Acquisition, on behalf of the system, of any employer security, real property, or loan.