Look at the equation co is a product reactant and a product reactant

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Every chemical equation has two sides, the left side and the right side, the two side are separated by an arrow.
The left side is the reactant side, those elements or compounds that are written on that side are all reactants. So, if the CO is one of the element on that side, then the answer is reactant. The right side is the product side, all the compounds written on that side are products. Thus, if CO is on that side,  then the answer is product. If it happens that CO appear on both sides, then that means that it is both a reactant and a product.

Reactant and a product - gradpoint

It's the only choice u got

Explanation:

just throw a ball to check ,if u can't trust gravity