Indian Institute of Foreign Trade 2010 Solved Paper

$\mathit{C}{\mathit{O}}_2$ emission by the US after 2 years $={\left(1-\frac{12.5}{100}\right)}^2\times 1200=918.75$ million tons.
The per capita income in US after 2 years $={\left(1+\frac{2}{100}\right)}^2\times 300=312.12$
Similarly, we can calculate the $\mathit{C}{\mathit{O}}_2$ emission and per capita income for remaining countries after two years from now.
$\mathit{C}{\mathit{O}}_2$ emission by the China after 2 years = 903.44 million tons.
The per capita income in China after 2 years $={\left(1+\frac{4}{100}\right)}^2\times 270=292.032$
$\mathit{C}{\mathit{O}}_2$ emission by the Japan after 2 years $=861.33$ million tons.
The per capital income in Japan after 2 years $={\left(1+\frac{3}{100}\right)}^2\times 240=254.616$
Hence, the required ratioTherefore, we can say option C is the correct answer.