问题如下：
3. With regard to Chen’s trades in Xydeo, do the institutional and retail trades both comply with CFA Institute Standards?
选项：
A. Only the retail trades comply.
B. Only the institutional trades comply.
C. Neither the retail nor the institutional trades comply.
解释：
B is correct.
Only the institutional trades comply with CFA Institute Standards. All the trades were processed on a net basis. Because the firm disclosed that institutional orders may be executed on a net basis, the institutional trades did not result in a violation. The firm disclosed to clients that in riskless principal trades, retail clients will receive the same execution price without mark-up. Executing the retail orders on a net basis with a $.01 mark-up resulted in a violation of Standards I(C) and III(B) relating to misrepresentation and fair dealing.
老师您好，这个case的6个题，我就做对了第一题，请问哪里有视频详细讲解（我找了一下当前app里放出来的课程，没找到）？如果没有视频讲解，请把3-6题的关键要点都解释一下呗，谢谢。