I found the whole exercise on the internet. These are the options:
"A) CaHCO3
B) C8H18
C) NO
D) K2CO3"
Correct answer: B) C8H18
This compound is called octane. In its combustion are envolved 2 molecules of C8H18 (octane) itself and 25 molecules of O2 (oxygen). This combustion/reaction leads to the formation of 16 molecules of CO2 (carbon dioxide) and 18 molecules of H2O (water). This is a compound that's quite popular due to its presence in gasoline.
