If the number of atoms in the reactants equals the number of atoms in the products, the equation is

the equation is said to be balanced

Explanation:

If the number of atoms in the reactants equals the number of atoms in the products, the equation is balanced

Explanation:

According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side. Thus chemical equations are balanced.

Thus in the reactants, there is 1 atom of carbon and 2 atoms of oxygen Thus there will be 1 atom of carbon and 2 atoms of oxygen in the product as well for reaction to be balanced.

the answer would be a