The propositions are:
(1) using solar panels
(2) burning fossil fuels
(3) generating nuclear power
(4) producing hydroelectric power
The right answer is 2
1 and 4 False because solar panels and hydroelectric are a solution to save the earth from pollution and global warming.
3 using nuclear energy is harmful to the earth but is not responsible for global warming.
2. Burning fossil fuels is the main responsible reagent for global warming due to the excessive release of CO2.