问题如下：
Monteo and Chaterji also discuss other approaches to asset allocation. Chaterji tells Monteo that he understands the factor-based approach to asset allocation to have two key characteristics:
Characteristic 1 The factors commonly used in the factor-based approach generally have low correlations with the market and with each other.
Characteristic 2 The factors commonly used in the factor-based approach are typically different from the fundamental or structural factors used in multi-factor models.
Monteo concludes the meeting with Chaterji after sharing his views on the factor based approach.
Which of the characteristics put forth by Chaterji to describe the factor-based approach is/are correct?
选项：
A.Only Characteristic 1
B.Only Characteristic 2
C.Both Characteristic 1 and Characteristic 2
解释：
A is correct.
The factors commonly used in the factor-based approach generally have low correlations with the market and with each other. This results from the fact that the factors typically represent what is referred to as a zero (dollar) investment or self-financing investment, in which the under-performing attribute is sold short to finance an offsetting long position in the better-performing attribute. Constructing factors in this manner removes most market exposure from the factors (because of the offsetting short and long positions); as a result, the factors generally have low correlations with the market and with one another. Also, the factors commonly used in the factor-based approach are typically similar to the fundamental or structural factors used in multifactor models.
老师你好，请问我的思路对不对：和market有low correlation的原因是因为在多因子模型中，market，size，value是三个因子互相独立，且根据线性回归的性质两个因子间不能存在强的线性关系。
