这道题是啥意思能解释一下吗，谢谢

问题如下：

Hollingsworth presents the long-term relative performance of Countries C and D, shown in Exhibit 3. Although both countries had below-average levels of per capita GDP 50 years ago, over time, the per capita GDP growth rate of Country C has risen rapidly and for nearly 20 years has been well above average. The growth rate for Country D, however, has risen more slowly. Today, Country C ranks among the advanced economies whereas Country D remains a developing nation.

Country D's current economic status can best be explained by past government policies that encouraged:

选项：

A.foreign investment. B.domestic substitutes. C.free trade.

解释：

Policies that encourage the production of domestic substitutes are inward oriented, attempting to develop domestic industries by restricting imports, despite the fact that it may be more costly to do so. As a result, the country would not benefit from the positive effects of integrating domestic industries with the global economy and benefiting from trade and foreign investment.

鼓励生产国内替代品的政策是面向国内的，试图通过限制进口来发展国内工业，尽管这样做的代价可能更高。因此，该国不会从国内工业与全球经济一体化以及从贸易和外国投资中获益的积极影响中受益。