Answer : The product formed in the combination reaction is, magnesium carbonate,

Explanation :
Combination reaction : It is a chemical reaction in which multiple substances or reactants combine to form a single product.
The balanced chemical reaction will be,

This reaction is a combination reaction in which the magnesium oxide react with the carbon dioxide to give magnesium carbonate as a product.
Hence, the product formed in the combination reaction is, magnesium carbonate,
