问题如下：
6. The surprise in which of the following had the greatest effect on fund returns?
选项：
A.Inflation on Fund B
B.GDP growth on Fund A
C.GDP growth on Fund C
解释：
C is correct.
Surprise in a macroeconomic model is defined as actual factor minus predicted factor. For inflation, the surprise factor is 2.2% – 2.0% = 0.2%; for GDP growth, the surprise factor is 1.0% – 1.5% = –0.5%. The effect on returns is the product of the surprise and the factor sensitivity.
考点：macroeconomic model
解析：一个factor对于Return的影响程度要综合考虑两个方面：一是factor的大小，二是股票对这个factor的敏感程度。因此影响程度要看surprise和 factor sensitivity乘积的绝对值（负值代表负面影响）。
A选项：1.5 × 0.2% = 0.30%
B选项：1.0 × –0.5% = –0.50%
C选项：1.1 × –0.5% = –0.55%
所以C选项对fund return的影响最大。
请问：求surprise对fund return最有影响，不是应该比较在不同Fund中相对应的surprise对总回报的占比比重吗？比如：1、Inflation on Fund B为什么不是（0.2%*1.6）/（4%+0.2%*1.6+（-0.5%）*0）呢？;2、GDP on Fund A:(-0.5%*1)/(2%+0.2%*0.5+(-0.5%)*1);3、GDP on Fund C:(-0.55%*1.1)/(3%+0.2%*1+(-0.5%)*1.1)
这样求出来就是Fund A中的GDP占比比重最大啊
