The answer is Separation of Powers
Answer:
oil produces CO2
coal produces CO2
uranium does not produce CO2 aka nuclear reactors as this process requires dipping the uranium rods into water creating steam and turning a turbine making energy
natural gas does create CO2 but less than coal and oil that is why natural gas is preferred as a energy source
Explanation:
'Horse Drawn Vehicles' were once the primary transportation method, and there were 3 involved animals, horses, mules, and oxen, although horses were the original go to for a carriage, due to fast movement, oxen soon became popular amoungst emigrants.