老师好，对比答案，我们做这类型的题目是不是必须要写duration-matching 的那3个条件呢？然后再解释
1）PV of asset ≥ PV of liabilities
2) Duration of asset = duration of liabilities
3) minimize the convexity
如果像我下面两个方式回答，哪个会拿满分呢？？我做题的时候写的是 i）这种方式
i）Portfolio A would best immunise the future liability
1. The present of value of portfolio A is larger than the present value of liability (USD 92,339.315 > USD 92,221,521), but portfolio B not meet this criteria
2. the macaulay duration of portfolio A is closely matched with the ten-year horizon of liabilities, but portfolio C not meet this criteria
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ii）Portfolio A would best immunise the future liability
1. The present of value of portfolio A is larger than the present value of liability (USD 92,339.315 > USD 92,221,521), but portfolio B not meet this criteria
2. the macaulay duration of portfolio A is closely matched with the ten-year horizon of liabilities, but portfolio C not meet this criteria
3) and the convexity of portfolio A is minimised after excluding portfolio B and portfolio C
谢谢老师
