What are the primary sources of radiation in a chemical rocket engine?

A)
Shock layer at the nozzle exit
B)
Rapid combustion of injector fuel
C)
De-excitation of internal modes of gas molecules
D)
Excitation of molecules in the combustion chamber

Correct Answer :   De-excitation of internal modes of gas molecules


Explanation : The molecules are excited in the combustion chamber. But these excited molecules de-excite in their internal modes causing radiation to be emitted.