Read the paragraph below and choose the best option indicating what 'their refers to . Due to the decreasing amount of fossil fuels, and the increase in their price for governments and consumers, Charles Darwin's express WOuld perfectly suit the ongoing competition for the remaining fossil fuels by powerful and wealthier countries. Many leading economically and politically in weaker and poorer economies for their rich ground on fossil fuels. But what are fossil fuels?

1)powerful and wealthier countries

2)many leading countries

3)weaker and poorer economies

4)fossil fuels