问题如下：
7 Based on Exhibit 1, which government policy has been most effective in helping Genovia achieve its second initiative?
选项：
A.Tax on fossil fuels
B.Subsidy on hydropower
C.Subsidy on other renewables
解释：
C is correct. At the end of Year 2, the compound annual growth rate (CAGR) for each sector is calculated as follows: (Year 2/Year 0)0.5 – 1
Fossil fuels = (426/462)0.5 – 1 = –4% Hydropower = (273/186)0.5 – 1 = 21% Other renewables = (154/97)0.5 – 1 = 26%.
The CAGR indicates that the 26% increase in production from the subsidy on other renewables has been more effective than the 4% decrease in production from the tax on fossil fuels or the 21% increase in production from the subsidy on hydropower. Thus, the subsidy on other renewables of 26% is the highest, indicating that this policy has been the most effective in helping Genovia achieve its second initiative.
考点：Regulatory Tools
解析：首先我们根据表格计算一下政府实施政策后，不同发电来源产电的变化。
Fossil fuels = (426/462)0.5– 1 = –4%
Hydropower = (273/186)0.5– 1 = 21%
Other renewables = (154/97)0.5 – 1 = 26%.
从计算结果看，石化燃料发电降低了4%，风力发电增加了21%，其他再生资源发电增加了26%。因此从环保节能的角度而言，其他再生资源收获的效果最大。
使用（year2-year0)/year0再开方，与(year2/year0)0.5-1求出来的值不应该都是年化增长率？为什么选择第二种计算方式？
