老师

问题如下：

选项：

A.set standards to ensure that all agents acting in the market are skilled.

B.promote fair and orderly markets.

C.ensure that systems are in place to prevent fraud.

解释：

A is correct. Regulators help solve agency problems by setting minimum standards of competence, not skill, for agents and by defining and enforcing minimum standards of practice.

B is incorrect. One of the objectives of market regulation is to promote fair and orderly markets in which traders can trade at prices that accurately reflect fundamental values.

C is incorrect. Regulators ensure that systems are in place to protect customers from fraud.