问题如下：
The board decides to
consider adding a mid-cap manager. McMahon presents candidates for the mid-cap portfolio.
Exhibit 2 provides fees and cash holdings for three portfolios and an index
fund.
Based on Exhibit 2, which portfolio will most likely have the lowest
tracking error?
选项：
A.Portfolio 1
Portfolio 2
Portfolio 3
解释：
Of the three portfolios, Portfolio 3 has the lowest cash holding and
the lowest fees. As a result, Portfolio 3 has the potential for the lowest
tracking error compared with the other proposed portfolios.
cash holdings高代表什么？这里的fee是trading cost吗
