问题如下：
Barry Smith Investment Management (Barry Smith) specializes in balanced account management for midsize pension plans. On 12 March 2006, a contribution of $2,265,000 is made to Dennett Electronics’ Pension Plan, which is included in Barry Smith’s Balanced Tax-Exempt Composite. This is the only external cash flow for March. Barry Smith invests the contribution on 13 March. The pension plan’s portfolio had a fair value of $16,575,000 at the beginning of March. For the purpose of calculating portfolio performance, how should Barry Smith handle the external cash flow? Assume that Barry Smith has adopted a large cash flow policy as of 1 January 2006, all external cash flows are assumed to take place at the end of day, and the 12 March 2006 cash flow meets the definition of "large".
解释：
Barry Smith must have a documented, composite-specific policy for the treatment of external cash flows and must compute time-weighted total returns that adjust for external cash flows. For periods beginning 1 January 2005, rate-of-return approximation methods must adjust for cash flows on a day-weighted basis (I.2.A.2). Accordingly, Barry Smith must use a return-calculation methodology that adjusts for daily-weighted external cash flows, such as the Modified Dietz method. However, the 12 March 2006 contribution to the Dennett portfolio represents 13.67 percent of the portfolio’s value, and it may be classified as a large external cash flow. Barry Smith must establish in advance a policy for the treatment of external cash flows for the Balanced Tax-Exempt composite. "Large" external cash flows may distort approximated returns. (See Sections 3.2, 3.5, and 3.9 of the reading.)
The 2010 version of the Standards includes a recommendation to value portfolios on the date of "all" external cash flows. This recommendation is effective for periods beginning on or after January 1, 2011 (I.1.B.1). As Barry Smith has adopted a large cash flow policy as of 1 January 2006 and assumes all external cash flows take place at the end of the day, given that the 12 March 2006 cash flow meets the definition of "large", the firm must value the portfolio as of the end of the day on 12 March 2006. Barry Smith would then compute sub-period returns for the March partial periods before and after the cash flow and link them to calculate a true time-weighted rate of return for the month of March. Alternately, if Barry Smith had adopted a "significant" cash flow policy for this composite and the 12 March cash flow met this definition, the firm would either determine that this entire portfolio be excluded from the composite for the month of March or treat the cash flow as a temporary new account (I.3.B.2).
老师，请问可以帮助解答下这道题吗？答案没看懂
