Answer: B, C

Item 4 of Article 26 of the "Code of Professional Conduct for Futures Practitioners (Revised)" stipulates that fair competition among peers is promoted and practitioners are strictly prohibited from investing in Return commissions to investors’ agents or introducers without the investor’s knowledge. Article 27 stipulates that practitioners shall not obstruct or refuse investors to entrust other institutions or practitioners to provide services, and there shall be a clear division of labor and collaboration between practitioners providing the same services.