Respuesta :
[tex]\huge{ \mathcal{ \underline{ Answer }\: \: ✓ }}[/tex]
Catalyst are substance that are added to a reaction in order to speed of the reaction.
And they remain the same before and after the reaction, hence the correct option is :
B. It remains unused.
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[tex]\mathrm{ ☠ \: TeeNForeveR \: ☠}[/tex]