Hydrogen has been used as a rocket fuel. Would you consider it a cleaner fuel than $CNG$? Why or why not?

(A) Yes,hydrogen is considered a cleaner fuel than $CNG$.
$CNG$ (Compressed Natural Gas) consists of hydrocarbons,which contain carbon.
When $CNG$ burns,it releases carbon-based pollutants like carbon dioxide and other greenhouse gases into the atmosphere.
In contrast,hydrogen combustion produces only water $(H_2O)$ as a byproduct.
Since hydrogen combustion does not produce carbon-based pollutants or harmful emissions,it is environmentally cleaner than $CNG$.