The correct answer is B. The best policy to prevent violation of Standard II(A)–Material Nonpublic Information is the establishment of firewalls in a firm to prevent exchange of insider information. The physical and informational barrier of a firewall between the investment banking department and the brokerage operation prevents the investment banking department from providing information to analysts on the brokerage side who may be writing recommendations on a company stock. Prohibiting recommendations of the stock of companies that are clients of the investment banking department is an alternative, but answer A states that this prohibition would be permanent, which is not the best answer. Once an offering is complete and the material nonpublic information obtained by the investment banking department becomes public, resuming publishing recommendations on the stock is not a violation of the Code and Standards because the information of the investment banking department no longer gives the brokerage operation an advantage in writing the report.

Answer C is incorrect because no exchange of information should be occurring between the investment banking department and the brokerage operation, so monitoring of such exchanges is not an effective compliance procedure for preventing the use of material nonpublic information.

B是正确的，这涉及到Standard II(A)–Material Nonpublic Information。建立防火墙，阻止内幕信息交流是防止违反Standard II(A)–Material Nonpublic Information的最佳策略。禁止给投行部的客户进行股票的推荐是另一种选择，但当重大非公开信息公开后就可以进行推荐买卖，不该加上永久性。因此B正确，而A错误。

C选项，投行部与业务部不该有信息上的交流，所以监管并非有效的程序，所以C错误