每一个答案可以解释一下吗？

问题如下：

Kata Rom is an equity analyst working for Gimingham Wealth Partners (GWP), a large investment advisory company. Rom meets with Goran Galic, a Canadian private wealth client, to explain investment strategies used by GWP to generate portfolio alpha for its clients.

Galic, who is 62 years old, decides to allocate C$2 million (representing 10% of his net worth) to an account with GWP and stipulates that portfolio assets be restricted exclusively to domestic securities. Although GWP has not backtested its strategies with such a restriction, it has backtested its strategies using a global index that includes domestic securities. Rom shows the following risk measures to Galic for three factor portfolios.

Which key parameter needs to be changed for a new backtest that includes Galic’s restrictions?

选项：

A.

Start and end dates

B.

Consideration of transaction costs

C.

Investment universe

解释：

C is correct. Investment universe represents the securities in which a strategy can potentially invest. Galic’s restriction to exclusively own domestic securities means the investment universe of a backtest for a strategy for Galic’s account should use a domestic rather than global investment universe.

A is incorrect. Galic’s restriction to domestic securities does not affect the start and end dates for a backtest.

B is incorrect. Galic’s restriction to domestic securities does not change the inclusion of transaction costs in the study.