问题如下：
The city also manages a separate, smaller bond portfolio for the Radford School District. During the next five years, the school district has obligations for school expansions and renovations. The funds needed for those obligations are invested in the Bloomberg Barclays US Aggregate Index. Kepler asks Ng which portfolio management strategy would be most efficient in mimicking this index.
Ng’s response to Kepler’s question about the most efficient portfolio management strategy should be:
选项：
A. full replication
B. active management
C. an enhanced indexing strategy.
解释：
C is correct.
Under an enhanced indexing strategy, the index is replicated with fewer than the full set of index constituents but still matches the original index’s primary risk factors. This strategy replicates the index performance under different market scenarios more efficiently than the full replication of a pure indexing approach.
Efficient一定是指成本低吗？不能理解成效果最好吗
