问题如下：
In order to generate a relatively higher expected return and maintain the sufficient funds to pay the future liabilities, the most appropriate approach to allocate the assets should be:
选项：
A.a surplus optimization approach.
B.an integrated asset–liability approach.
C.a hedging/return-seeking portfolios approach.
解释：
C is correct.
考点：liability-relative asset allocation的三种方法
解析：hedging/return-seeking portfolios approach, 又被称为two-portfolio approach，将资产划分成两个部分，其中hedging portfolio用于覆盖未来现金流的付出，通常投资固定收益产品，return-seeking portfolio独立管理追求收益率，这种方法正好可以满足题目中的两个要求。
请问为什么不能用surplus optimization
