Answer:
2Mg + O₂ → 2MgO
Explanation:
Given reaction:
2Mg + O₂ → 2MgO
This is the only combination reaction from the given set of choices.
A combination reaction is a synthesis reaction.
In this kind of reaction, a single product is formed from two or more reactants.
E.g
A + B → C
The formation of a compound from constituent elements falls into this category of reaction.