考的哪个知识点？没看懂什么意思

老师，您好，这题完全没看懂，您帮讲讲

请问margin interest paid 的9800如何算出的？

Mittal Tine’s investment portfolio currently consists of stocks in two companies, 40% in Drysdale Banking and the remaining amount in Clamped Oil. Performance measurement information for these two stocks is given in the table below: The covariance between the two stocks is 0.001. Tien is considering adding a third stock, Hillbillies Investors. Hillbillies Investor’s correlation coefficient with the current portfolio is 0.38. Which of the following statements is least accurate? A With Hillbillies added to the portfolio, the variance could be 0.026. B As Tien diversifies, he will reduce the portfolio's unsystematic risk. C The standard deviation of returns for the current portfolio is 15.5%. 这题答案错了吧，因该是w的平方乘以方差+w的平方乘以方差+2倍w1w2方差1方差2肉12

A，B，C分别代表什么业务，为什么是A，考的哪个知识点

b怎么理解啊？看不懂下面的解释

38的讲义跟视频不一样 是考还是不考阿

Reading 38 视频跟讲义的不一样 这章节考还是不考阿

老师第13题，考的是IIIB.还是IVB啊？感觉A和C都对

intellectual property是不是所谓的离职后自己的知识技能还可以用？research应该也没有违反呀？