Answer: Neutralization Reaction
Explanation: Acid-Base Indicator are the substances which are responsible for the observance of the color change in the titration mixture due to the change in pH at the end point.
Acid -Base reactions are those in which acid and base reacts to get neutralized and formation of the salt takes place.
When the amount of acid becomes equal to the amount of base, end point is reached where the color of the solution changes.
This reaction is neither a decomposition reaction as the reactant is not getting decomposed into simpler elements nor a combustion reaction as it is not taking place in presence of oxygen . It can be a part of combination reaction but it is more primarily known as Neutralization reaction.