Answer:
B. Combustion .
Step-by-step explanation:
Hello.
In this case, since this reaction is started by pentyne and oxygen which are converted to carbon dioxide and water, we can infer this is a combustion reaction because it involves the burnt of a fuel, in this case the pentyne, by using oxygen in order to yield carbon dioxide and water, which are smaller molecules than the original pentyne.
It is important to notice that these reactions are very exothermic because they go to break the C-H bonds in the fuel which release a considerably high amount of energy.
Best regards!