问题如下：
Eunice, an analyst from an investment company, recently made the following statements about an equally-weighted portfolio consisting of a large number of assets：
Statement 1: Average variance of the individual assets contributes the most to the volatility of the portfolio.
Statement 2: Standard deviation of the individual assets contributes the most to the volatility of the portfolio.
Statement 3: Average covariance between all pairs of assets contributes the most to the volatility of the portfolio.
Which statement is most correct?
选项：
A.Statement 1.
B.Statement 2.
C.Statement 3.
解释：
C is correct.
As the number of assets in the same weighting portfolio increases, the co-movement between assets also increases. As the number of assets contained in the equally weighted portfolio increases, the contribution of each individual asset's variance to portfolio volatility decreases.The following equation for the variance of an equally weighted portfolio illustrates these points:
老师 这道题没有很理解 能详细解答下吗。 我自己的理解是 当这个资产数量很多时 因为他题目里说a large number of ,然后那个equal weighted的式子 cov的影响很大，那根据cov的式子 单个资产的方差不是会影响吗 选b这样
